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I joined a team where the controller was 800 lines long, the business rules were scattered between the controller and the DbContext , and "to run the tests, spin up a SQL Server in Docker" was a sentence I heard every week. The fix was Clean Architecture. The argument I had with the team lead was about how to actually structure it. We argued for two weeks. Then I built this template so the next person wouldn't have to. This is the Clean Architecture .NET 8 starter template I wish someone had handed me on day one. Four projects, strict dependency direction, domain entities that own their own invariants, and an Application layer you can unit test with Moq — no database required. The whole repo is on GitHub , MIT-licensed, runs with dotnet run , and ships with xUnit tests, JWT auth, Swagger, Docker, and CI. This post is the explanation of why each project exists, what goes in it, and what I learned the hard way about getting Clean Architecture right in .NET. The problem Clean Architecture solves The naive way to build a .NET Web API is one project, one folder structure, and "everything talks to everything": MyApp/ Controllers/ ProductsController.cs ← HTTP stuff OrdersController.cs ← HTTP stuff + business rules Services/ ProductService.cs ← business rules + DbContext.SaveChanges Data/ AppDbContext.cs ← EF Core, entities Models/ Product.cs ← POCO with public setters This works for the first 1,000 lines. By 5,000 lines, the controller is doing five things at once. By 10,000, "to test this, I need a database" is the answer to every test question, and your CI takes 20 minutes because every test run spins up SQL Server. Clean Architecture says: separate the business rules from the HTTP boundary, separate the database from the business rules, and enforce it with project references. A controller is allowed to call a service. A service is allowed to call a repository. A repository is allowed to know about EF Core. Nothing is allowed to know about anything "above" it in the chai

I uploaded a 40-page PDF of an internal API spec, asked "what's the rate limit for the search endpoint?", and got back: "100 requests per minute per API key, with bursts up to 200. See section 4.2 of the document." With citations. In about three seconds. The whole stack runs on my laptop. It cost me $0 in LLM credits during development because Ollama is free and local, and the embedder I used is also free and local. The repo is here — issues and PRs welcome. This is the build log. Not a tutorial where every step works the first time — a build log where I tell you which decisions held up and which ones I redid. The problem most "chat with your PDF" demos have Every "chat with your PDF" tutorial I read in early 2025 had the same shape: open OpenAI, paste your API key, call gpt-4 with a 50-page PDF stuffed into the context window, get an answer, pay $0.03 per question, repeat. That works for a demo. It does not work for a tool you'd actually use at work, because: The PDF might contain customer data, internal pricing, or unreleased features. You do not want that going to OpenAI's training pipeline or anyone's logs. The cost adds up. If your team uses it 50 times a day, that's $45/month per seat. The model hallucinates on long PDFs anyway. Stuff 100 pages into a 128k context window and the model starts forgetting the middle. The fix is RAG (Retrieval-Augmented Generation) — don't send the whole PDF, send only the 3-5 chunks that are actually relevant to the question. The rest of the work is the same: embed the chunks, embed the question, find the closest matches, send those to the LLM with the question. But the cost and the privacy story both improve by 100x. The actual ask: Upload a PDF. Ask questions. Get answers from the document with citations, in under 5 seconds, with no data leaving my laptop and no monthly bill. The architecture One .NET 8 solution, one React app, one Ollama process, zero cloud dependencies. [ PDF Upload ] | v +-------------------+ chunks +-------

Last Tuesday my API gateway caught a NullReferenceException , streamed it to a dashboard in real-time, and pushed a draft code fix to the browser tab of the on-call engineer — before I finished reading the error myself. That sentence used to be vendor marketing. Now it's just my Program.cs . This is the architecture post-mortem. I built it on weekends. It runs in Docker. It cost me exactly $0 in LLM credits during development because Groq's free tier is generous and Ollama works as a swap-in. The repo is here — issues and PRs welcome. The problem most .NET teams have Production errors are caught, logged to a file, and forgotten. Engineers find out from a Slack ping twenty minutes later, if at all. By the time someone looks, the original request context is gone, the user's session has expired, and the stack trace is buried four layers deep in System.* calls. "Self-healing" is a word vendors use to mean "auto-restart the pod." I wanted something better. The actual ask: When an exception is thrown in service A, give the engineer (a) a clear root cause, (b) a suggested fix, and (c) a draft code patch — in under 30 seconds. Not a magic black box. Not an auto-applied patch. Just: catch the error, give the model the right context, push the analysis to a human in real-time, and let the human close the loop. The architecture One .NET solution, four projects, four NuGet packages, no new infrastructure beyond what you probably already have. [ HTTP request ] | v +-------------------+ enqueue +---------------------+ | SmartLogAnalyzer. | ---------------------> | Hangfire (Redis) | | Api | +----------+----------+ | (ErrorHandling | | | Middleware) | v +-------------------+ +---------------------+ | SmartLogAnalyzer. | | Worker | | (ErrorProcessingWorker) +-----+-------+-------+ | | AI call | | persist v v +-----------+ +-----------+ | Semantic | | MSSQL | | Kernel + | | (ErrorLog | | Groq LLM | | table) | +-----+-----+ +-----------+ | v +---------------------+ | SignalR Hub | | (

Thinking about trying FtrIO? The new CLI makes it easy to start with just one feature flag If you've been curious about FtrIO (the .NET feature toggle library that replaces if (featureFlags.IsEnabled(...)) with a [Toggle] attribute woven directly into your compiled IL) but weren't sure where to start, the experimental release of FtrIO.onetwo just made that first step a lot smaller. You don't need to commit to a full migration. You don't need to rip out your existing flag library. You just need one method and 20 minutes. What FtrIO.onetwo does FtrIO.onetwo is a .NET CLI audit tool. Its default mode scans your source tree, finds every FtrIO toggle reference, and tells you exactly what's live right now: dotnet tool install --global FtrIO.onetwo --version 1.1.1-experimental ftrio.onetwo --source C: \P rojects \M yApp But in this experimental release it does two new things: ftrio.onetwo import : pulls your current flag state from LaunchDarkly, Flagsmith, flagd, environment variables, or an HTTP endpoint directly into appsettings.json . Your existing flag library keeps working unchanged. ftrio.onetwo migrate : scans your .cs files for LaunchDarkly or Flagsmith SDK call patterns using Roslyn, cross-references them against your live flag state, and generates a report showing exactly what each flag would look like in FtrIO and how to migrate it. The "try it on one flag" workflow The migrate report categorises every flag it finds: ✅ Ready to migrate : boolean flag, no targeting rules, straightforward [Toggle] replacement ⚠️ Needs review : targeting rules, number flags, needs a decision ❌ Cannot migrate : JSON flags, recommend moving to IConfiguration For every ready flag it shows the suggested refactor. Something like: new - checkout - flow → NewCheckoutFlow File : Services \ OrderService . cs : 42 Current code : if ( client . BoolVariation ( "new-checkout-flow" , user , false )) { ValidateCart (); ApplyDiscounts (); ProcessPayment (); } Suggested action : Extract the if bloc

Every weekday a single, opinionated rule for senior C#/.NET engineers using Cursor. Here's the full week in one read — canonical posts live on the Agentic Architect blog . 7 daily senior rules Rule 14: Sealed By Default Sun 21 Jun Mark every class sealed unless inheritance is explicitly planned. Stops Cursor inventing accidental inheritance hierarchies "for flexibility." Small but measurable virtual-call perf wins too. → Permalink on the blog Rule 13: Strongly-Typed IDs Sat 20 Jun OrderId as record struct OrderId(Guid Value) beats raw Guid everywhere. Stops the AI passing a CustomerId where an OrderId was expected — a bug the compiler can't catch with primitive obsession but catches instantly with domain primitives. → Permalink on the blog Rule 12: IOptionsSnapshot Over Raw Config Fri 19 Jun Business code should never call IConfiguration directly. Strongly-typed IOptions or IOptionsSnapshot bindings only. The AI loves to "just grab the config value" — refuse it and force a settings class with validation attributes. → Permalink on the blog Rule 11: Rethrow, Don't throw ex Thu 18 Jun throw ex resets the stack trace. throw preserves it. Cursor gets this wrong about 40 percent of the time when generating catch blocks. Rewrite any naked throw ex to throw unless the exception has been explicitly wrapped. → Permalink on the blog Rule 10: AsNoTracking for Reads Wed 17 Jun Every read-only EF Core query should call AsNoTracking. Add a rule that recognises query methods returning DTOs (not entities) and inserts the call. Cursor never does this by default and your read perf degrades silently across releases. → Permalink on the blog Rule 9: Scoped Capture in Singleton Tue 16 Jun The single most expensive .NET runtime bug: a Singleton holding a Scoped service. Cursor cheerfully writes this without warning. Audit constructor parameters of any class registered as Singleton — if any are typically Scoped (DbContext, repositories, MediatR sender), flag it before merge. → Permalink on

Originally published at https://allcoderthings.com/en/article/csharp-generics-list-t-dictionary-tkey-tvalue In C#, generics are used to increase type safety and flexibility. Generic classes and collections eliminate the need for runtime type casting and avoid unnecessary boxing and unboxing operations, improving performance and reducing the risk of errors. Before generics were introduced, collections such as ArrayList stored elements as object . When a value type like int was added to an ArrayList , it had to be boxed (converted to object ), and later unboxed when retrieved. This boxing/unboxing process caused additional memory allocations and performance overhead. With generic collections like List<T> and Dictionary<TKey,TValue> , elements are stored in their actual types, eliminating these costs and making the code both safer and faster. List List<T> is a generic collection that dynamically stores elements of a specific type. T specifies the type of elements the list will contain. using System ; using System.Collections.Generic ; var numbers = new List < int >(); numbers . Add ( 10 ); numbers . Add ( 20 ); numbers . Add ( 30 ); foreach ( int n in numbers ) Console . WriteLine ( n ); // Output: // 10 // 20 // 30 Note: Unlike arrays, List<T> can grow and shrink dynamically. Dictionary Dictionary is a generic key–value collection. TKey specifies the type of the key, and TValue specifies the type of the value. using System ; using System.Collections.Generic ; var students = new Dictionary < int , string >(); students [ 101 ] = "John" ; students [ 102 ] = "Mary" ; students [ 103 ] = "Michael" ; foreach ( var kv in students ) Console . WriteLine ( $" { kv . Key } → { kv . Value } " ); // Output: // 101 → John // 102 → Mary // 103 → Michael Note: Each Key in a dictionary must be unique. Attempting to add the same key again will cause an error. Creating Your Own Generic Classes You can also define your own generic types, not just use built-in collections. This allows you

This is Part 13 of my series on the Microsoft Agent Framework. You can read the original post over on lukaswalter.dev . In the previous article , we looked at workflows. Workflows make sense when the process itself needs structure: state, checkpoints, events, human approvals, and resumable execution. This post is the bridge from Agent Framework into RAG. I plan on doing a full RAG deep dive sometime later. The practical question for now is smaller: How do I connect an Agent Framework agent to private application knowledge without stuffing every document into the prompt? For agents, RAG is less about adding more text and more about giving the agent a controlled retrieval path. The agent should fetch the right context at the point where it needs it. Agents do not know your private data Your company documents, product catalog, tickets, rules, policies, runbooks, and internal knowledge base live outside the model. The model has generic knowledge. Your application has private knowledge. Treat those as separate systems. You can paste some private data into the prompt, and for a demo that may be enough. But this falls apart quickly: full documents are expensive to send repeatedly long prompts are fragile stale documents may sit next to current ones users may not be allowed to see every source long context still needs selection The last point is easy to underestimate. A larger context window lets you send more text. It does not decide which text is correct, current, relevant, or permitted. Do not give the agent all knowledge. Give it the right context at the moment it needs it. Retrieval owns that job. The minimal RAG shape The basic RAG loop is small: user question -> retrieve relevant chunks -> pass chunks to the agent -> agent answers using that context For documents, the longer pipeline usually looks like this: documents -> chunks -> embeddings -> vector store -> search -> retrieved context -> agent response Documents are split into smaller chunks. Those chunks are embe

Class, Record, and Struct serve as blueprints for creating new objects. Classes Classes are the foundational building blocks of Object-Oriented Programming (OOP). Blueprint and instance // blueprint public class Person { public int ID { get ; set ; } public string Name { get ; set ; } } // instance var p = new Person { ID = 1 , Name = "Mirza" } Inspection Printing the class instance in the console will just display it's name: var p1 = new Person { ID = 1 , Name = "Mirza" }; Console . WriteLine ( p1 ); // Person To print the actual, we'd need print each property explicitly: Console . WriteLine ( p1 . ID ); // 1 Console . WriteLine ( p1 . Name ); // "Mirza" Mutation C# classes are mutable, meaning the originally set values can be altered: var p1 = new Person { ID = 1 , Name = "Mirza" }; Console . WriteLine ( p1 . Name ); // "Mirza" p1 . Name = "Armin" ; Console . WriteLine ( p1 . Name ); // "Armin" That said, this can be tweaked by changing the accessor the class property. public class Person { public int ID { get ; set ; } public string Name { get ; init ; } // <-- } This time around if we try to change the value of the Name property after initialization, the C# compiler will start to complain. var p1 = new Person { ID = 1 , Name = "Mirza" }; p1 . Name = "Edis" ; // ❌ The init accessor allows you to create properties that can only be assigned a value during object initialization. Memory location Classes are reference types and are allocated on the heap. If we create two distinct class objects and assign one to the other, both objects will point to the exact same reference in memory: var p1 = new Person { ID = 1 , Name = "Mirza" }; var p2 = new Person { ID = 2 , Name = "Mirza" }; p1 = p2 ; p1 . Name = "Sead" ; Console . WriteLine ( p1 . Name ); // Sead Console . WriteLine ( p2 . Name ); // Sead If we change a value in one of the objects, it will be reflected in both. Equality Two class instances (objects) aren't equal even if they share the same values: var p1 = new P

A couple of years ago, I built a custom flashcard app. I had a huge list of words and sentences in Japanese that I collected in an Excel file. I wanted an app that could easily take them and display them on flashcards. The flashcard app was useful, but the main issue was that I could only use it on my laptop. This meant that when I wasn't home, I had no access to it. I made some updates so that I could deploy it to Azure and now I can use it on the train or at the park. I wanted to share the app and lessons learned during development. What It Does The app is a straightforward spaced repetition flashcard tool. You create collections, fill them with cards (front/back/optional notes), and review them. After each card you rate your recall: Button Meaning Easy Remembered without effort Good Remembered correctly Hard Remembered with difficulty Again Forgot (resets to day 1) Ratings feed the SM-2 algorithm, which is the same algorithm as other popular spaced repetition apps like Anki. Cards that are easy get pushed further and further into the future. Cards that are difficult will come back sooner. After a while, you're just reviewing what you actually need to review. There's also a 45-second timer per card. If it expires before you complete the card, it automatically counts as Again (Resets to day 1). Before the timer, I found it easy to lose focus or open another tab and forget about the current card. This has helped me stay focused for longer and stay on this task. The CSS is specifically designed to be mobile friendly. The Tech Stack Frontend: Blazor WebAssembly (.NET 10) Backend: ASP.NET Core minimal API (.NET 10) Database: Azure SQL (Basic DTU tier) Hosting: Azure Static Web Apps (frontend) + Azure App Service F1 free tier (backend) I mostly use C# at work, so Blazor WASM was a natural fit. The whole app shares models and flows together without jumping between languages. Importing Cards from Excel This Excel import function is one of the main reasons I made this app.

A complete solution: expressive range types in your domain layer, full PostgreSQL translation in your data layer - no compromises at either end The Two-Column Trap Almost every developer has written it at least once. An object with two date properties: public class MemberSubscription { public int Id { get ; set ; } public int MemberId { get ; set ; } public DateTime StartDate { get ; set ; } public DateTime EndDate { get ; set ; } } Imagine you need to answer a seemingly simple question in a booking system: "Is this subscription still active, and does it conflict with the proposed new one?" With two bare fields, that code ends up looking something like this: // With two bare DateTime fields — the check you always end up writing public static bool IsActive ( MemberSubscription sub , DateTime at ) => sub . StartDate <= at && ( sub . EndDate == default || sub . EndDate > at ); public static bool ConflictsWith ( MemberSubscription a , MemberSubscription b ) { // Partial overlap: a starts inside b if ( a . StartDate >= b . StartDate && a . StartDate < b . EndDate ) return true ; // Partial overlap: b starts inside a if ( b . StartDate >= a . StartDate && b . StartDate < a . StartDate ) return true ; // b is fully contained by a if ( a . StartDate <= b . StartDate && a . EndDate >= b . EndDate ) return true ; // What about open-ended subscriptions? What about same-day boundaries? // What about inclusive vs exclusive end dates? ... return false ; } It looks perfectly reasonable. But start asking questions — as Steve Smith (Ardalis) does in his essay on making the implicit explicit — and you notice how much invisible knowledge this design requires. Should EndDate ever precede StartDate ? The type system doesn't say. Can a subscription have a null end date meaning it never expires? Nothing in the model communicates that. Is a subscription that ends today still active at 11:59 PM? Ask three developers and get three answers. The EndDate == default sentinel for open-ended subsc

C# 14: The field Keyword — Cleaner Properties, Zero Boilerplate Every C# developer has been there. You start with a clean auto-property, then requirements change and you need to add a tiny bit of validation. Suddenly that one-liner explodes into six lines of boilerplate — a private backing field, a getter that just returns it, a setter that assigns it. The logic is two words. The ceremony is everything else. C# 14 fixes this with the field keyword: a contextual keyword that refers to the compiler-synthesized backing field of a property, letting you write custom accessor logic without ever declaring an explicit field. The Problem: Boilerplate Tax on Simple Properties Auto-properties are one of C#'s best quality-of-life features. This is clean: public string Username { get ; set ; } But the moment you need to trim whitespace on assignment, that cleanness evaporates: private string _username = string . Empty ; public string Username { get => _username ; set => _username = value . Trim (); } You now have six lines — and four of them exist only to hold the shape of the pattern together. The backing field _username is not carrying any meaningful design weight. Its only job is to be a storage slot that Username uses privately. You already know the compiler creates one for auto-properties. You are just forced to make it visible so you can reference it. This is the boilerplate tax. You pay it every time you add even the smallest piece of logic to a property. Why field Exists The C# language team has discussed this friction for years. The challenge was finding syntax that is: Unambiguous — no conflict with existing identifiers Familiar — consistent with how value works in setters Scoped — only meaningful inside a property accessor The solution landed in C# 14: the contextual keyword field . Just like value refers to the incoming assignment in a setter, field refers to the hidden backing storage the compiler manages for the property. It is contextual, which means it only acts

TL;DR — AI assistants are producing C# that looks correct and passes review, but reintroduces production regressions we spent years training out of teams. I'm trying to find out whether other .NET teams see the same patterns — and what's actually catching them before merge. More AI-generated C# is landing in pull requests. Most of it is fine. But a specific category keeps slipping through — and it's the dangerous one, because it compiles, tests pass, and a human skim says "looks good." The pattern The code compiles. Tests pass. Review approves. Production finds out. These aren't syntax errors. They're architectural intent violations — the kind of thing a senior dev would have caught in review before PR volume tripled. Five regressions I keep seeing 1. EF Core read paths without AsNoTracking() Fine in dev. Expensive on a hot read path in prod. // ❌ Looks reasonable. Tracks entities you never mutate. var orders = await _db . Orders . Where ( o => o . CustomerId == id ) . ToListAsync ( cancellationToken ); Fix direction: AsNoTracking() on read-only queries, or a team convention documented in CLAUDE.md / Copilot instructions. 2. Captive dependency (scoped service in a singleton) Compiles. Runs. Wrong state across requests. // ❌ Singleton lives forever; scoped dependency does not. services . AddScoped < IOrderRepository , OrderRepository >(); services . AddSingleton < ReportCache >(); // ctor takes IOrderRepository Fix direction: align lifetimes, or inject IServiceScopeFactory instead of capturing scoped services. 3. Dropped CancellationToken The method accepts cancellation. The downstream call ignores it. // ❌ Signature honours cancellation; body doesn't. public async Task RunAsync ( CancellationToken cancellationToken ) { await Task . Delay ( 500 ); // overload with token exists } Fix direction: forward cancellationToken to every downstream async call that accepts one. 4. Swallowed exception Failure disappears. Monitoring stays green. // ❌ "Handle errors gracefully" —

The first post went over some of its capabilities. Over the past week Edict went v1.0, adding cursors for reading projections after command dispatch (to close some eventual-consistency gaps), a new type of projection that holds state inside the Orleans grain directly instead of a table, saga timeouts, schedules, an improved skills package and MCP server that ships with Edict, and more. Edict has now grown to over 75,000 lines of code and more than 1000 tests, and contains several deep mechanisms that have been fixed, broken, and fixed again. It is well past the point where I can hold all of Edict in my head. This post is about working with AI on large codebases, which I expect to be the first problem most software engineers have to solve. The context problem Years ago I was talking to a PhD candidate whose area of research was Natural Language Processing (NLP). He explained to me that one of the most difficult NLP problems was context. If a colleague says they need to pop out to pick their kids up from school, a scene can form in your head: one with a school, the layout of the road, people waiting, walking, driving, the environs. You may never have seen the school your colleague mentioned, but you can form a rich scene from your accumulated experience and use it to drive the rest of the conversation with a shared understanding. LLMs ingeniously dodge this entire issue by making it your problem. Just a word-probability machine Strip away the chat window and a Large Language Model (LLM) is doing one thing: predicting the next token. Give it a run of text and it returns a probability distribution over what comes next, samples one, appends it, and repeats. Companies like OpenAI and Anthropic then beat it into shape using techniques like supervised fine-tuning and reinforcement learning, which tune those probabilities in meaningful ways. That is why Claude is always telling me "Good framing" or "You've spotted...". It even called me "Bold" on one occasion. The probabilit

A while back, I needed to integrate SMS into a .NET project. Giant SMS had a REST API, but no official .NET client. The only existing library was a PHP one from 6–7 years ago, and it only covered two methods: send and getBalance. So I built my own. It now has nearly 2,000 downloads on NuGet. Here's exactly how I did it. The Problem Wiring up raw HTTP calls to the Giant SMS API in every project gets repetitive fast: Manually setting Authorization headers Remembering which endpoints use token auth vs. username/password Deserializing responses every time Scattering credentials across your codebase I wanted something that felt native to .NET. Configure once in appsettings.json , register with DI, and just call a method. Designing the Public API The first decision was the interface. I wanted consumers to never touch HttpClient directly, and I wanted methods that mapped clearly to what the API actually does: public interface IGiantSmsService { bool IsReady { get ; } Task < SingleSmsResponse > SendSingleMessage ( string to , string msg ); Task < SingleSmsResponse > SendMessageWithToken ( SingleMessageRequest messageRequest ); Task < BaseResponse > SendBulkMessages ( BulkMessageRequest messageRequest ); Task < SingleSmsResponse > CheckMessageStatus ( string messageId ); Task < BaseResponse > GetBalance (); Task < SenderIdResponse > GetSenderIds (); Task < BaseResponse > RegisterSenderId ( RegisterSenderIdRequest senderIdRequest ); } Seven methods, the full surface of the API, no more, no less. The IsReady property is a small but useful addition. It lets consumers do a quick sanity check at startup rather than discovering a missing token on the first SMS send: csharp _isReady = !string.IsNullOrWhiteSpace(_connection.Token) && !string.IsNullOrWhiteSpace(_connection.Username); Handling Two Auth Methods This was the most interesting design challenge. The Giant SMS API uses two different authentication schemes depending on the endpoint: Token-based (Basic Authorization header) —

What can I say. Anyone claiming that F# is good mostly for finance and data processing and C# for everything else, has probably never written a single line of practical F# code. In previous two parts of the article, I tried to demonstrate that with F# you can achieve the same goals as with C#, but with less verbose, repetitive, structural code. How it started. At some point, developers realized that global state with unrestricted data access causes many side effects, producing insecure, error-prone, and hard-to-maintain code as software grows larger. That is when the idea emerged to bring data and the code operating on it together into a single unit, restricting direct access to the unit’s internal state and making software more secure and predictable. This is how data encapsulation was born. Alongside encapsulation, abstraction was introduced — the process of hiding how behavior works. Encapsulation ( hiding data ) and abstraction ( hiding behavior ) remain two foundational pillars of Object-Oriented Programming. And that is how OOP has worked ever since — developers bring data and behavior together ( classes ) and define abstractions for them ( interfaces ). For example, for C# developers — including myself — this has become a daily routine. And we rarely question it, because OOP languages like C# leave us little choice but to structure code this way. But if you ask yourself whether this repetitive routine is always necessary, the answer is — no. You don’t need OOP concepts to build stateless, streamlined request–response, data-processing pipelines, because in such systems there is no long-lived state to hide and protect. You have a request, and almost immediately you have a response. After that, everything is gone. That is what I tried to demonstrate in the first two parts of this article by applying FP concepts. And even if you have a classical desktop application, you don’t always need to approach it in an OOP way. Functional programming handles side effects no

This is a submission for the GitHub Finish-Up-A-Thon Challenge Originally, I didn't plan to join...

Overview PDF text extraction is a common pre-processing step in data pipelines — ingesting research papers, legal documents, or reports before embedding or indexing. Both pypdf and PdfPig are pure managed-code parsers: no native binaries, no OCR, no system PDF renderer. They implement the same PDF specification operations in their respective languages. This makes the benchmark unusually clean: the performance difference is entirely due to language execution speed, not library architecture differences. Benchmark Setup 200 recent arXiv PDFs (mixed technical papers, 5–40 pages each). Tested on subsets of 10, 50, 100, and 200 files. Both libraries extract all text from all pages; output is validated for page-count agreement and character-count agreement within 15% (pypdf and PdfPig decode whitespace and encoding tables slightly differently). Results PDFs Pages Python (pypdf) .NET (PdfPig) Speedup 10 ~120 ~0.9 s ~230 ms 3.9× 50 ~600 ~4.2 s ~810 ms 5.2× 100 ~1,200 ~8.5 s ~1.4 s 6.1× 200 ~2,400 ~17 s ~2.7 s 6.2× The speedup grows slightly with corpus size, suggesting pypdf has a per-document startup cost that compounds as PdfPig's JIT gets warmer. Why PdfPig Is Faster PDF parsing is byte-heavy: every page is a stream of PostScript-like operators (move, show text, set font, etc.). Each operator must be lexed, looked up in a dispatch table, and executed against a graphics state machine. In Python, each operator dispatch is a Python method call — the CPython bytecode interpreter has overhead per call regardless of what the method does. In .NET, the JIT compiles the dispatch loop to native code the first time it runs; subsequent pages pay only the cost of the actual work. Additionally, PdfPig's content-stream parser operates on ReadOnlySpan<byte> — zero-copy slicing through the raw page bytes with no intermediate string allocations. pypdf builds Python string objects for each token. Key Code // PdfPig — zero-copy span-based page extraction public Result Extract ( string path )

Overview PageRank is the canonical graph algorithm. NetworkX implements it in pure Python — its dict-of-dict adjacency representation means every power-iteration step dispatches millions of Python attribute lookups. When the graph has 1.8 million nodes and 28.5 million edges (Wikipedia category hyperlinks), those lookups dominate the runtime. The .NET replacement uses a CSR (Compressed Sparse Row) matrix — two flat int[] arrays for the graph structure — and TensorPrimitives for the SIMD-accelerated normalization step inside each iteration. Benchmark Setup Five SNAP datasets of increasing size: Dataset Nodes Edges wiki-Vote 7,115 103,689 soc-Epinions1 75,879 508,837 web-Stanford 281,903 2,312,497 web-Google 875,713 5,105,039 wiki-topcats 1,791,489 28,511,807 Algorithm: power-iteration PageRank, damping=0.85, tol=1e-6. Both implementations converge to identical top-10 node rankings. Results Dataset Python (NetworkX) .NET (CSR) Speedup wiki-Vote (103k edges) ~0.8 s ~100 ms ~8× soc-Epinions1 (508k edges) ~8 s ~600 ms ~13× web-Stanford (2.3M edges) ~120 s ~5 s ~24× web-Google (5.1M edges) ~5.5 min ~12 s ~28× wiki-topcats (28.5M edges) ~47 min ~60 s ~47× The speedup grows with graph size because NetworkX's Python dispatch cost scales with edge count, while the CSR inner loop is a tight JIT-compiled SIMD pass. Why CSR Beats NetworkX NetworkX represents each node's neighbors as a Python dict. Iterating the adjacency in one power-iteration step means: Calling G.neighbors(node) — a Python method call Iterating a dict — unboxing int keys, chasing heap pointers Accumulating a float into another dict value — another boxing step That happens for every edge, every iteration, roughly 50–80 times to convergence. CSR collapses the graph to two arrays: rowPtr[n+1] (where each node's neighbors start) and colIdx[edges] (the neighbor list). Iterating neighbors of node v is a tight C loop from rowPtr[v] to rowPtr[v+1] . No Python objects, no dict hashing, no pointer chasing. Key Code // P

As part of my game development journey, I recently created Hidden Collector , a Unity-based game where players explore levels and collect hidden items while progressing through different challenges. This project started as a way for me to improve my Unity and C# skills, but it quickly became an opportunity to learn about game design, UI systems, audio management, scene transitions, and player experience. What I Worked On While building Hidden Collector, I implemented: Player movement and interactions Collectible item systems Multiple game levels UI menus and game screens Audio and sound effects Progress tracking Game flow and scene management Challenges During Development One of the biggest challenges was making different game systems work together smoothly. Something as simple as collecting an item often required updates to UI elements, game state management, and progression systems. Debugging these interactions taught me a lot about organizing Unity projects and writing maintainable code. What I Learned This project helped me gain experience with: Unity Engine C# scripting Game architecture UI implementation Audio management Debugging and testing Most importantly, I learned that building complete projects teaches far more than following tutorials. Play the Game You can try Hidden Collector here: https://sinxcos07.itch.io/hiddencollector Screenshots What's Next? I'm continuing to improve my game development skills by building new projects, experimenting with different mechanics, and learning more about creating engaging player experiences. If you try the game, I'd love to hear your feedback. By Suryansh Sinha (sinxcos07) Connect With Me GitHub: https://github.com/sinxcos07 LinkedIn: https://www.linkedin.com/in/suryansh-sinha/ Play Hidden Collector: https://sinxcos07.itch.io/hiddencollector

There's a question that keeps surfacing across engineering teams — sometimes in architecture reviews,...