Engineering leadership for cloud-native, AI-enabled, high-scale fintech.
Notes, patterns, and case studies on engineering leadership, cloud-native architecture, generative & agentic AI, and risk technology by Rajeev Singla.
Agentic AI for Lending — a three-part deep dive
The model is the easy part. Building agentic AI that survives a real credit pipeline — bureau timeouts, regulatory timers, and the auditor in the room — is the actual job. Here is the series.
Topics, organized for engineers and leaders
A modern catalog of the original APICODE.IO knowledge base — restructured into seven durable categories you can actually browse.
AI Engineering
Foundations of AI, machine learning workloads, computer vision, NLP, document intelligence, knowledge mining, generative AI and agentic AI patterns for production systems.
Cloud & DevOps
Containers, microservices, infrastructure-as-code, CI/CD pipelines, GKE, AWS deployments, observability, and the toolchain that ships production fintech systems.
System Design
Strategy pattern, configuration-driven orchestration, decision platforms, account linking, scalable APIs, and service composition patterns for high-volume systems.
Engineering Leadership
Operating notes for engineering leaders: measuring team health, running 1:1s, managing individuals, building credibility, performance management, and feedback craft.
Data & Platforms
Database internals, MongoDB aggregation, replication and sharding, feature flag platforms, and integration patterns for data-heavy workloads.
Algorithms & Interviews
Top algorithm patterns, problem walk-throughs, and a practical guide for system-design and language-specific technical interviews.
Projects & Case Studies
Selected case studies on credit and fraud risk technology, rule engines, platform rewrites, cloud migrations, and digital transformation across fintech and healthcare.
Outcomes from leading high-volume fintech platforms
A snapshot of the most measurable wins from the past few years of risk technology, decisioning platforms, and engineering leadership.
Spearheaded Lending Tree integration at Jenius Bank, opening a high-volume aggregator channel.
Aggregator integration delivering net-new top-of-funnel volume into the loan origination platform.
Cut decisioning P99 from 200ms to 5ms by migrating off a legacy SaaS rule engine.
Scaled core decisioning from 72 to 240 requests, enabling significant business growth.
Market App: Serverless Financial Intelligence Platform
A clean rebuild of a market-alerts and autotrading platform that retires ECR/Fargate, moves four backend services to Lambda zip APIs, and serves the SPA plus APIs through CloudFront on financial.apicode.io.
The target architecture reduces Docker/ECR/Fargate operational overhead, keeps paper trading auditable through DynamoDB, and creates a repeatable Terraform workflow for financial.apicode.io.
Read project spotlight- Used AI as an architecture partner to compare Fargate, Lambda image, and Lambda zip deployment models and settle on the simplest operational target.
- Used AI to draft the destroy/rebuild sequence, identify blast-radius boundaries, and keep apicode.io hosting, bootstrap state, and legacy local IB experiments out of scope.
- Used AI-assisted refactoring to convert container/FastAPI services into API Gateway v2 Lambda handlers while preserving local-only experimentation paths.
Modernized articles, ready to read
A handful of recently modernized articles across AI, system design, cloud, and engineering leadership.
Market App: Serverless Financial Intelligence Platform
A clean rebuild of a market-alerts, pairs, quant, and autotrading platform into Lambda zip APIs behind API Gateway and CloudFront, with AI-assisted planning and auditable Alpaca execution.
A Practical Map of Quantitative Finance Algorithms
An industry-standard map of the core algorithms used in quantitative finance, grouped by application area with purpose, use cases, and practical notes.
AI Foundations: From Machine Learning to Agentic AI
A modern, opinionated entry point into AI workloads — machine learning, computer vision, NLP, document intelligence, knowledge mining, generative AI, and agentic AI.
Agentic AI in Lending: Orchestration Beats the Model
Agentic AI is already in lending — every credit decisioning workflow is a stitched-together agent system. The hard problem is not the model; it is the orchestration that turns each step into an auditable, accountable action.
Pre-built paths instead of a wall of links
Five guided paths — pick the one that matches what you’re trying to learn this quarter.
AI Engineering Path
From AI workloads to applied generative and agentic AI, with an emphasis on production hardening.
- 1AI Foundations: From Machine Learning to Agentic AI
Agentic AI for Lending Series
A three-part deep dive on building agentic AI for personal loans — why orchestration beats the model, a reference architecture, and the seven principles for reliable loan orchestration.
- 1Agentic AI in Lending: Orchestration Beats the Model
- 2A Production Architecture for Agentic Lending
- 37 Principles for Reliable Loan Orchestration
Cloud Native Foundations
Containers, Docker, microservices, CI/CD, and the local toolchain that makes the rest possible.
- 1Engineering Tooling Baseline
- 2Containers and Docker for Production Engineers
- 3Microservices, CI/CD, and the Real Tradeoffs
System Design Path
Configuration-driven orchestration, strategy patterns, and a reference component map for an internal orchestrator.
- 1Configuration-Driven Orchestration in Practice
- 2Orchestrator Service: A Reference Component Map
Engineering Leadership Path
How to operate as a tech leader: measure team health, manage individuals, run 1:1s, and give feedback that lands.
- 1Measuring the Health of an Engineering Team
- 2Managing Individuals
- 3Running Effective 1:1s
- 4Feedback Templates That Actually Land
Interview Prep Path
Algorithm patterns and decisioning case studies that mirror the interview loops at modern fintech and platform companies.
- 1Top Algorithm Patterns for Interviews
- 2Case Study — Decisioning Platform at Jenius Bank
The AI workloads worth understanding in 2026
Quick-look cards for the seven workloads that show up in production AI systems, from machine learning to agentic AI.
Machine Learning
The foundation of most AI systems. Models that learn from data and generalize to new inputs.
Computer Vision
Interpret cameras, video, and images for inspection, search, safety, and analytics.
Natural Language Processing
Understand and generate language for chat, summarization, search, and structured extraction.
Document Intelligence
Process forms and high-volume documents into structured data with quality assurance.
Knowledge Mining
Turn unstructured content into searchable, governed knowledge for the whole org.
Generative AI
Generate text, images, code, and audio under controllable constraints and guardrails.
Agentic AI
Combine models with tools and policies to take multi-step actions on behalf of users.
Want to talk shop?
Open to conversations about engineering leadership, risk technology, decisioning platforms, AI in regulated industries, or modernizing legacy stacks.