Courses

• Python FundamentalsComprehensions and generators, dataclasses with type hints, and Enum with match: the habits that make Python read like Python.
• Algorithms in PythonBinary search, a stable sort with key= and recursion over nested data, in plain Python and proven by pytest-style tests.
• Agents and orchestrationIntent routing, tool orchestration and guardrails: the pieces that turn a tool-calling model into an agent.
• Async TypeScriptA typed event emitter, typed promise utilities, abortable work and async generators: J1's patterns with the types as the subject.
• Modern JavaScript, the useful partsDestructuring, generators, private fields and Proxy: the everyday language features that make modern JavaScript read better.
• Refactoring to strictLoose TypeScript that compiles today but is silent about its own shape; add the annotations until the compiler starts catching bugs.
• Prompt engineeringBuilding prompts that shape the model: roles, templates and few-shot examples.
• Tokenizers, by handHow text becomes tokens: word splitting, byte-pair encoding, a vocabulary, and encode/decode that round-trips.
• Async JavaScript, by handPromises, retry, concurrency limits and async generators, written from scratch and tested with real awaits.
• Typed domain modellingBranded ids, state machines as unions, Result pipelines and a schema validator: the types that make a domain impossible to misuse.
• Embeddings and RAGChunk a document, retrieve the relevant piece, and assemble a grounded answer.
• Refactoring JavaScriptFour classic smells, four working-but-ugly starters, and tests that only go green when the shape of the code changes.
• Data structures in JavaScriptA linked list, a min-heap, an LRU cache and a trie, built from scratch so you know what the array is doing for you.
• Streaming and structured outputCollect a stream of chunks, buffer partial JSON, and validate it into a typed value.
• Advanced typesConditional types, key remapping, recursion, variadic tuples and brands — types computed from types, verified by the compiler.
• Data structures in TypeScriptA generic heap, an LRU cache, a trie and an immutable list — the same structures, but generic, so the types flow through.
• JavaScript Design Patterns IICommand, State, Middleware and Memento: the patterns that give you undo, valid transitions, composable pipelines and saved state.
• TypeScript for JavaScript developersTypeScript without the ceremony: annotations, narrowing, generics and the built-in type operators, starting from real JavaScript.
• Function calling and toolsParse a tool call, dispatch it, and loop model-and-tool until the answer arrives.
• Embeddings and similarityTurn documents into vectors, measure their similarity, and find the nearest neighbour.
• Algorithms in JavaScript IISliding window, dynamic programming, Dijkstra and backtracking: the next tier of interview and systems algorithms, hand-written and tested.
• Decoding: logits to textHow a model's output scores become the next token: greedy, softmax, top-k, sampling and beam search.
• A tiny neural netA linear layer, cross-entropy loss and a single attention head: the forward pass, from scratch.
• Modern PHP, the boring parts done rightValue objects, collections and failures in plain PHP 8.4, no framework required.
• JavaScript Design PatternsStrategy, Observer, Factory and Decorator, rebuilt the idiomatic JS way.
• Refactoring PHP: keep the tests greenFour classic smells, four working-but-ugly starters, and tests that only go green when the shape of the code changes.
• TDD in PHP: a bank ledgerGrow an Account class one failing test at a time: deposits, an overdraft rule, a statement, and transfers that cannot half-happen.
• Advanced Algorithms in PHPDynamic programming, Dijkstra with SplPriorityQueue, tries, topological sort and union-find: the interview classics, in PHP that reads well.
• TypeScript that means somethingUse the type system to make wrong states unrepresentable, so the compiler fails the bug before a test has to.
• Hexagonal Architecture in PHPPorts, adapters, command handlers, domain events and aggregate invariants: a task-tracking slice built the way a framework-free core should be.
• PHP FundamentalsStrict types, arrays that do the work, and enums with match: the three habits every PHP 8 file is built on.
• Algorithms in PHPBinary search, a stable insertion sort and recursion over nested data, written in plain PHP and proven by tests.
• PHP 8.4 Deep DiveProperty hooks, asymmetric visibility, array_find and friends, lazy objects and generators: the newest PHP, with runnable exercises.
• Data Structures in PHPA stack, a fixed-size queue and a linked list, each built from scratch so you know what the array is doing for you.
• TDD with JavaScriptBuild a shopping cart one red-green-refactor step at a time.
• PHP Design PatternsStrategy, Pipeline, Specification and Builder, the way PHP 8 interfaces, enums, closures and readonly classes make them.
• Algorithms in JavaScriptBinary search, a two-stack queue, merge sort and grid BFS, hand-written and tested.