Hands-on technical leadership, with 20 years of craft behind it.
I'm Dhruva Sagar, a software craftsman in Bangalore, two decades into architecting, building, and shipping software in Rust, Go, Ruby, Python, Elixir, TypeScript, and Java. Today I work with early-stage teams as a fractional CTO and technical advisor: architecture, roadmap, hiring, and the hard decisions. The same decisions I've been making while leading engineering teams for 12+ years, backed by the ISB CTO Program. Beyond the core craft, my deepest practice is agentic engineering: building complex software with coding agents, at scale. I still write and ship open-source software myself, much of it that way.
Core philosophy
Build like it will outlive the roadmap.
Agentic engineering at scale
The deepest thread in my current research
Lattice is the testbed: two coding agents, Claude Code and opencode, build against one shared capability surface, driving a multi-threaded editor core through phase ledgers, design documents, and CI-ratcheted performance gates.
The learnings: agents need capability gates, not prompt prayers; plugin hosts that sandbox their output; trust modes that scale from "review everything" to "ship it"; and a record of the system they can read. That practice, agents at scale without losing the craft, is what I bring to teams building complex software.
Architecture before velocity
The fast path is a trap if it compounds into a ball of mud. I design for the system's tenth year, not its tenth sprint. I take technical debt as a decision, not an accident.
Slow, deliberate building
In open water you don't kick harder, you look further ahead. Sustainable, stable systems come from measured, deliberate progress, the same discipline as a decade with the cube.
Hands-on leadership
I don't just draw diagrams. I write the foundational scaffolding, set the golden paths, and mentor by example, leading the work, not just the roadmap.
Engagement models
Ways to work together
Three ways to work together, from a few hours a week to full-time delivery. Predictable commitment, no equity required.
Advisory
Senior judgement on demand: stack selection, RFC reviews, technical audits, and honest answers to hard questions. The lightest engagement, a few hours a week on your cadence.
Book a call →Technical expertise
Hands-on work without a full-time hire: architecture, code, and infrastructure reviews, modernization and digital transformation, agentic engineering workflows. More involved than advisory, still not full time.
Book a call →Fractional CTO & delivery
End-to-end product and feature delivery: roadmap, architecture, hiring, and leading the build. For teams that need a technical leader, effectively full time.
ISB CTO Program · Class of '25
Book a call →Not sure what you need? Email me and we'll figure it out.
The stack, at a glance:
Selected work
Things I've built and shipped
Recent work
Lattice
Founder & architect, pre-1.0, building in public
A modal, GPU-accelerated, plugin-first text editor in Rust: vim's editing grammar, Emacs-class extensibility through sandboxed WASM plugins, and a UI thread that never blocks, with a ~3,600-line design document behind it.
Built with two coding agents against one shared capability surface. The full practice is detailed in my core philosophy.
Creator
An open-source framework for AI-native engineering knowledge systems, capturing what an organization knows in a form both engineers and AI systems can use. The ideas behind my Knowledge Operating System writing, productized.
Creator
Run fractional-CTO engagements out of Org mode: one active client, one capture prefix, one agenda dashboard. The record of an engagement and the rhythm of running it live in the same file.
Creator
A Claude Code plugin that turns Ruby and Rails upgrades into a phased, verifiable process: audit, plan, fix, verify, commit. Built from a decade of upgrades done the hard way.
Client work
Principal Consultant · 12+ years
Twelve years architecting and shipping web solutions for product companies: TuneCore, Aisle, Moove, JiffleNow, Gaea Global, Klstr, and more. Rails, Go, React, AWS, and the discipline to keep it maintainable.
Earlier career: ActiveSphere, Dharana, SAP Labs, IBM
Senior Developer → Software Engineer · 2006 to 2014
Before Tarkalabs: web solutions for Pulse Energy, Bounty Me, Live Network, and Health Highway at ActiveSphere and Dharana; a business-intelligence UI framework at SAP Labs; and in-house products at IBM.
Side projects
stromalytics
Prototype
AI-powered swimming technique analysis: upload a video of a swim, get biomechanics metrics and a personalised coaching report with drill recommendations. Pose estimation with RTMPose, coaching reports with Claude.
kridha pratiyogita
Prototype
A multi-tenant sports management platform for organizations, teams, and tournaments, built in Rust with Leptos and PostgreSQL. The name means "sports competition" in Sanskrit.
Prototype
Create and share business canvases to pitch startup ideas. The canvas that used to live on a whiteboard, made shareable. Rust backend, React frontend.
cubeschool
Prototype
A speed-cubing school: beginner layer-by-layer courses with an embedded algorithm player and validated practice. More than a decade with the cube, productized.
Prototype
A console Rubik's cube timer in Rust, for speed cubers who live in the terminal: a timer that lives there too.
Open source
50+ repositories in total: github.com/dhruvasagar
Writing
Notes on code, craft, attention, and the examined life.
Contact
Let's build something worth keeping.
Leadership and advisory for early-stage teams, agentic engineering at scale, or a second pair of eyes on an architecture, in any stack and any language. I'm happy to talk it through.
Book a call