— Engineering notes
How we actually build the hard parts.
Deep dives into the systems we design, ship, and keep running in production.
Written by the senior engineers who actually built these systems — no filler, no generic advice. Client and product names stay under NDA; the numbers and trade-offs are real.
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Projects shipped
Proposals, Not Actions: The Control Plane Behind Autonomous Infrastructure Agents
An LLM agent that hallucinates a destructive change does it with total fluency and zero hesitation — and at fleet scale, that stops being an anecdote and becomes a rate. This is the control plane we built for a multi-tenant agentic infrastructure platform: deterministic policy gates, blast-radius scoring, DAG-scoped locking, decision provenance, and just-in-time credentials that give you the leverage of autonomous agents without their blast radius.
August 6, 2026 · 13 min read
Read articleMobile app development cost: a line-item model and a quote comparison template
Mobile app development cost is not one number but a list of line items; its share is set by the number of screens and states, the back end and admin panel, features, integrations, platform choice and maintenance. This article gives no price figures. It offers a ten-line cost model, the ongoing costs of store accounts and requirements with official sources, and a template that compares three quotes on the same scope. A difference between quotes can often come from a difference in scope.
October 29, 2026 · 16 min read
Read articleHow to take over an unfinished software project: a step-by-step audit plan
When you take over an unfinished software project, first secure what can disappear: access to the repository, hosting, domain, database and third-party accounts. Then follow a step-by-step audit plan: a clean-machine install, a restore from backup, security and data health, and a feature inventory. The decision (continue, partial rewrite or start over) comes from a seven-dimension matrix scored 0 to 2 and is written down with its reasons. How long it takes depends on the code, documents, access and platforms, and is stated in the written quote.
October 29, 2026 · 17 min read
Read articleHow to read a software proposal: 12 red flags and a copy-ready SOW template
Read a software proposal starting from the scope, not the price: look for what is out of scope, the acceptance criteria, which delivery each payment depends on, and who owns the accounts and the code. Any line whose answer is not in writing may be a cost left outside the proposal. This article gives a ten-section proposal skeleton, 12 red flags, comparison tables, an example in which a one-line proposal becomes a scope document, and a copy-ready 12-heading scope of work (SOW) template. It is not legal advice.
October 29, 2026 · 19 min read
Read articleIs your vibe-coded app production-ready? A 15-point audit
A working prototype is not a production-ready app. Before you open an app written with AI tools to real users, audit the risks across fifteen items: secrets, authentication, authorization, input validation, the database, backups and restore, environments, error monitoring, dependencies, tests, performance, payments, personal data, cost and ownership. If any item on secrets, identity, access control, input validation, backups, payments or personal data has failed, do not go live. This article shows how to check each item and what counts as a pass.
October 27, 2026 · 24 min read
Read articleDesigning for the Link You Don't Have: Offline-First Coordination for an Autonomous Survey Fleet
A fleet operator's aircraft spend roughly a third of every sortie with no usable link to the ground — and the events that must never be lost happen inside that window. Here is the CRDT and delay-tolerant networking architecture we built so degraded connectivity costs fidelity, never safety data.
July 21, 2026 · 13 min read
Read articleA Price That Goes Backwards Is a Liability: Building a Sub-80ms Market-Data Fan-Out in Nineteen Days
A boutique derivatives desk needed live prices on thousands of trader terminals in under 80ms — and needed those prices to never flicker backwards, even under load. This is the sequencing discipline, backpressure design, and tail-latency instrumentation it took to deliver both, inside a four-week engineering window.
June 9, 2026 · 12 min read
Read articleNobody Is Coming: 41,000 Custom Energy Endpoints, From Bare PCB to Real-Time Analytics
A utility needed settlement-grade 15-minute energy data from 41,000 circuits bolted inside energized switchgear, on an eight-year battery, with no realistic possibility of a return visit. Off-the-shelf modems failed on both physics and economics, so we designed the hardware — and everything above it — ourselves.
May 14, 2026 · 19 min read
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Every post above traces back to a real decision on a real client project. If you're facing something similar, let's talk it through.