Johnston, Iowa · Live classes in US Central Time
§The catalog
Python, TypeScript, Rust, Algorithms, System design, Databases, Testing and Debugging & tools. Every course is taught live to 8 people or fewer and costs $8.64 to $148.64. None of them can be bought without talking to us first.
32 of 32 courses
From an empty file to a package other people can read, then fast enough to keep.
Variables, loops, functions and files, written in a plain editor before any notebook or framework gets involved. For people who have never programmed, or who have copied code without knowing why it ran.
Syntax · Functions · Files · The REPL
Modules, type hints, dataclasses and the parts of the standard library you keep rewriting by hand. You turn a 600-line script into a package a colleague could pick up on a Monday.
Type hints · Dataclasses · Packaging · pathlib
Tasks, timeouts, cancellation and the one blocking call that froze everything. You write a crawler that stays polite under a rate limit and stops cleanly when it is told to.
Tasks · Timeouts · Cancellation · Rate limits
Profilers, vectorization, C extensions and the honest benchmark that decides whether any of it was worth doing. For people whose Python works and is now too slow to keep.
cProfile · NumPy · Cython · Benchmarks
JavaScript understood properly first, then types that refuse the bad states.
Values, functions, objects and promises, and then the types that describe them. For people who learned JavaScript by pasting and would like to know what their code actually does.
Functions · Promises · Modules · Types
Unions, narrowing, generics and the discriminated union that replaces a page of if statements. You type a messy API response until the compiler refuses every state that should not exist.
Narrowing · Generics · Unions · strict
HTTP, streams, worker threads and error handling, starting from Node's built-in modules. You ship a small service, then remove dependencies until only the ones that earn their place are left.
node:http · Streams · Workers · Errors
Conditional and mapped types, infer, and the library typings you have been afraid to open. For people who maintain shared code and want its types to explain it.
Conditional types · Mapped types · infer · Declarations
Ownership until it feels ordinary, ending with a chess engine of your own.
Ownership, borrowing, structs, enums and the compiler errors that are trying to help. Built for people who know one other language and have bounced off Rust at least once.
Ownership · Borrowing · Enums · Cargo
Result, Option, traits, iterators and the ? operator, used until they feel ordinary. You write a command-line tool that fails loudly, early and helpfully.
Result · Traits · Iterators · CLI
Threads, channels, Send and Sync, Arc and Mutex, then async with Tokio. You spread work across every core and let the type system prove nothing is shared that shouldn't be.
Threads · Channels · Tokio · Send & Sync
Bitboards, move generation, perft, minimax with alpha-beta pruning and a transposition table. Six weeks to an engine that knows every legal move and finds a mate in three.
Bitboards · Move generation · Alpha-beta · perft
Cost, structure and search, worked on paper before anyone types a line.
Big-O, arrays, hash maps, sorting and binary search, drawn on a whiteboard before they're typed. You learn to say why one approach is faster, not just that it is.
Big-O · Hash maps · Sorting · Binary search
Recursion, trees, BFS, DFS, Dijkstra and topological sort, applied to dependency graphs and route maps instead of puzzles. You build a pathfinder and explain every step it took.
Recursion · BFS & DFS · Dijkstra · Topological sort
Subproblems, memoization and tabulation, taught from the recursive version you already understand. Three weeks, a dozen problems, and the moment it stops feeling like a trick.
Memoization · Tabulation · Recurrences · Knapsack
Minimax, alpha-beta, iterative deepening and Monte Carlo tree search — the ideas inside every board-game AI, worked on tic-tac-toe, Connect Four and finally chess.
Minimax · Alpha-beta · MCTS · Heuristics
Boxes, arrows and the trade-offs between them, from one server to many.
Clients, servers, databases, caches and queues, drawn as boxes and then argued about. For developers who ship features and have never been asked to draw the system they run on.
Requests · Caches · Queues · Diagrams
Load balancing, replication, partitioning and the cache invalidation everyone warns you about. You redesign one service three times as its traffic grows and defend every trade-off out loud.
Load balancing · Replication · Partitioning · Caching
A problem statement, the alternatives you rejected, and the diagram that ends a meeting early. You write a real design document, hear it reviewed by the group and revise it twice.
Trade-offs · Alternatives · Diagrams · Review
Consensus, clocks, idempotency, retries and partial failure, shown on a lab cluster that breaks on purpose. For engineers who own services that depend on other services.
Consensus · Clocks · Idempotency · Partitions
SQL, schemas, indexes and transactions — the part that outlives every rewrite.
SELECT, WHERE, JOIN, GROUP BY and NULL, asked of a dataset you would actually want answers from. You stop exporting to a spreadsheet to answer a question the database could.
SELECT · Joins · GROUP BY · NULL
Tables, keys and constraints that stop wrong rows at the door. You design a schema for a booking system, then watch the group try to break it with rows that only look valid.
Keys · Constraints · Normal forms · Relationships
B-trees, EXPLAIN ANALYZE, statistics and the index that made a query slower. You take a sluggish endpoint from seconds to milliseconds and can say exactly which line did it.
B-trees · EXPLAIN · Statistics · Covering indexes
Isolation levels, locks, MVCC and the lost update nobody noticed for a year. You reproduce each anomaly on purpose, then choose the cheapest level that prevents it.
Isolation · MVCC · Locks · Anomalies
Tests worth keeping, and the refactoring they make safe on code you inherited.
Assertions, fixtures and the habit of writing the failing test first. Two weeks in any language, for people who know they should test and have never seen it done well.
Assertions · Fixtures · Test first · Coverage
Characterization tests, seams, small steps and the rename that touched forty files safely. You work in a deliberately tangled codebase and leave it easier to change than you found it.
Seams · Characterization · Small steps · Legacy code
Generators, shrinking and properties that say what code must always do. You find the edge case your example tests missed, and then the three behind it.
Generators · Shrinking · Invariants · fast-check
Time, randomness, concurrency, networks and the flaky test everyone reruns. You make the untestable corners of a real service deterministic and delete every sleep.
Flaky tests · Fakes · Determinism · Contracts
Git, the shell, a method for bugs and the profilers that settle arguments.
Commits, branches, merges, rebase and the reflog that gets you back from almost anything. For people who still keep a copy of the folder, just in case.
Branches · Rebase · reflog · Conflicts
Pipes, grep, find, jq, small scripts and the one-liner that replaces an afternoon of clicking. You build the little tools you will reach for every day for years.
Pipes · grep & find · jq · Scripts
Hypotheses, bisection, breakpoints and the bug that vanishes when you look at it. You predict before you run, then check — a written method in place of guesswork.
Hypotheses · git bisect · Breakpoints · Logs
perf, flame graphs, strace, eBPF and the system call hiding behind a slow request. For people who have run out of print statements and need to see what the machine is doing.
perf · Flame graphs · strace · eBPF
White to play
Pick a course, or just write to us. Either way, you talk to the person who would teach you before anything is paid.