Pharosyne
Engineering notes

Engineering notes

Practical notes for deciding what to build, what to audit, and what to avoid before an AI project reaches production.

12Articles
51Min read
01
3 min read

Repair an AI-generated app: scope the first fix

How to scope a first paid repair for an app built with AI, reproduce the failure and decide whether a rewrite is actually needed.

AI-Assisted DevelopmentArchitectureSoftware Repair
02
3 min read

Subcontracting an AI integration: brief, acceptance and handover

How an agency can assign one AI module with clear ownership, acceptance checks and a handover its team can use.

AI IntegrationAgenciesSoftware Delivery
03
5 min read

Retry agent tool actions without duplicating their effects

Use persistent operation identifiers, explicit unknown outcomes and reconciliation to control retries of external actions in LLM integrations.

AI AgentsIntegrationsIdempotency
04
4 min read

Prevent cross-tenant document leaks in RAG

Check access before retrieval and test document leakage through cached answers, citations and source links in a multi-tenant RAG application.

RAGSecurityMulti-tenant
05
4 min read

AI consulting in Madrid: choose the work you need

How to choose an AI review, a scoped integration or technical leadership, with deliverables you can assess before agreeing a project.

AI ConsultingRAGAI Agents
06
5 min read

What a RAG and agent audit should deliver

Scope an AI audit around a release decision, with reproducible findings, permission tests and concrete acceptance criteria for remediation.

AI AuditRAGAI Agents
07
4 min read

Remote AI consulting: agree the work, reviews and handover

A working agreement for remote AI projects across Europe and Latin America: ownership, time zones, review material, access and technical handover.

Remote AI ConsultingRAGAI Agents
08
4 min read

Starting a remote fractional AI CTO engagement

Define a first fractional AI CTO engagement through decision ownership, technical reviews, hiring responsibilities and a clear point to reassess the work.

Fractional CTORemoteAI Leadership
09
5 min read

One production agent: tools, state and execution limits

Design an agent runtime that authorises tool calls, records operation outcomes and recovers from failures before allowing external changes.

AI AgentsLLMArchitecture
10
4 min read

Fractional CTO, adviser or engineer: which role do you need?

Choose between implementation, technical advice, fractional leadership and a full-time CTO by examining the work and decisions your startup needs covered.

Fractional CTOStartupTechnical Leadership
11
5 min read

RAG or fine-tuning: diagnose the failure first

Separate missing evidence from inconsistent model behaviour, then compare retrieval, prompting and fine-tuning against a defined acceptance test.

RAGLLMFine-tuning
12
5 min read

When dividing work between agents earns its cost

Assess parallel work, separate permissions and agent handoff contracts against their coordination cost before adopting a multi-agent architecture.

AI AgentsLLMArchitecture