Breaking
YC P26 — Atrisa builds AI agents for analog circuit design FOUNDERS — Ex-KLA & Texas Instruments engineers behind the company PRODUCT — Design, debug & simulate circuits in natural language PIVOT — Formerly Refortif AI, now focused on analog ROADMAP — Reasoning today, layout next, post-Si debug after YC P26 — Atrisa builds AI agents for analog circuit design FOUNDERS — Ex-KLA & Texas Instruments engineers behind the company PRODUCT — Design, debug & simulate circuits in natural language PIVOT — Formerly Refortif AI, now focused on analog ROADMAP — Reasoning today, layout next, post-Si debug after
Company Profile · Semiconductors & AI

Atrisa Wants to Teach AI the One Thing It Still Can't Do: Design Analog

Frontier models can write your code and pass your exams. Ask them to design an op-amp and they flail. Atrisa, a Y Combinator P26 startup, is building agents for the last hand-crafted corner of chip design.

There is a strange asymmetry in artificial intelligence right now. A language model can draft a legal brief, refactor a codebase, and explain quantum mechanics to a ten-year-old. Hand that same model the schematic for a two-stage amplifier and ask it to fix the phase margin, and it starts guessing. Analog circuit design - the discipline behind every power regulator, radio, and sensor front-end on the planet - remains stubbornly resistant to the tools that automated almost everything around it. Atrisa is a bet that this is the corner worth taking.

Atrisa, part of Y Combinator's Spring 2026 (P26) batch and based in San Francisco, builds AI agents for analog circuit design. The pitch is compact: describe a circuit in plain English, and the agent helps design it, debug it, and run the simulations. The company frames its product as "an assistant engineer right by your side" - not a replacement for the human, but a tireless second set of hands that has, in Atrisa's words, "internalized the intuition of an analog engineer."

2026
Founded
P26
YC Batch
SF
Headquarters

01 — The ProblemWhy the smartest models go quiet on analog

Digital chip design was largely automated decades ago. Logic synthesis, place-and-route, formal verification - the digital world runs on tooling that turns intent into silicon with minimal hand-holding. Analog never got that gift. Designing an industry-grade analog circuit leans on what engineers politely call "tribal knowledge": undocumented rules of thumb, hard-won intuition, and proprietary company data that lives inside senior designers' heads and internal wikis. None of it made it into the training set of a frontier model.

That is the gap Atrisa is built around. A general model has read the internet but has never watched a seasoned designer stare at a Bode plot and mutter that the compensation cap is too small. It doesn't feel parasitics. It doesn't know which topology a given company reaches for when the spec sheet says low noise and low power at the same time. Atrisa's argument is that this knowledge can be encoded - and that whoever encodes it first owns a real moat.

Right now, frontier LLMs struggle to make analog circuits. The knowledge lives in people, not documents.— On the problem Atrisa is built to solve

02 — The ProductDescribe it, design it

Atrisa's interface is a chat window, but the machinery behind it is specific to circuits. The agent reasons about a design hierarchically - breaking a system into blocks, matching topologies to specifications, and checking its own work against the physical realities that trip up naive designs: reusability, interference, parasitics, and layout. It plugs into the tools engineers already use, including process design kits (PDKs) and existing design documentation, so it augments a workflow rather than demanding a new one.

You
Describe
Agent
Reason
Agent
Design
Agent
Debug
Sim
Simulate
The loop. From a plain-English request to a simulated result - Atrisa's agents run the round trip an analog engineer usually walks by hand.

There is also a multi-agent angle. In a real design team, work stalls when everyone needs the one person who understands the bias network. Atrisa lets engineers hand pieces of a design to collaborating agents so blocks can move forward in parallel, without waiting on a single expert's calendar.

Illustrative — gain & phase margin from a compensated amplifier
dB freq PM ≈ 38°
Reading the curve. Phase margin and gain-bandwidth are the kind of numbers a designer chases for hours. The agent is built to reason about them, not just render them.

03 — The FoundersPeople who shipped silicon first

Atrisa's credibility starts with its team. This is not a group of generalists who discovered semiconductors on a whiteboard. The founders worked inside the industry before trying to automate it.

Sayan Mitra
Co-founder & CEO
Former AI Research Engineer at KLA; Electrical Engineering, IIT Madras.
Atman Kar
Co-founder & CTO
Former Texas Instruments engineer; builds the core reasoning system.
Rithik Jain
Co-founder & COO
Leads go-to-market and customer experience.

The company was originally named Refortif AI - a detail that still shows up in the founders' email addresses on the refortif.ai domain - before rebranding to Atrisa and sharpening its focus onto analog. Y Combinator group partner Nicolas Dessaigne backs the company.

04 — The CompetitionWhere Atrisa sits on the board

The honest competitor is the status quo: an experienced human doing the work by hand inside legacy EDA tools from Cadence and Synopsys. General-purpose LLM assistants are the other pole - fast and fluent, but unreliable the moment a problem needs real circuit understanding. A handful of AI-for-chip startups are circling the broader space. Atrisa's distinction is narrowness on purpose: it is built for analog, by analog people.

ApproachUnderstands analogFits existing workflow
General LLM assistantUnreliableYes
Legacy EDA toolsVia the humanYes
Manual expert designDeeplySlow / scarce
AtrisaBy designPDKs & docs

05 — The MarketA bottleneck worth widening

Analog and mixed-signal design is a choke point in nearly every chip. Every phone, electric vehicle, hearing aid, and satellite depends on analog blocks designed by a comparatively small pool of experts - a pool that isn't growing fast enough to meet demand. If Atrisa's agents let one engineer do the work of several, or let a strong digital engineer venture into analog with a competent guide, the leverage is obvious.

The parts that resist automation the longest tend to be the ones worth the most once you crack them.— The thesis, in one line

Atrisa's roadmap reads like a company that knows the terrain. Circuit reasoning and design first. Layout next. Post-silicon debug after that. Each step goes deeper into the physical stack, and each is a place where tribal knowledge, not textbook formulas, decides who wins. As a business, the shape is enterprise SaaS: agents sold to semiconductor and hardware teams, wired into their proprietary PDKs and workflows. The company is small - a founding team of ex-semiconductor engineers - and early. But the problem it picked is the kind that rewards depth over breadth.

Whether Atrisa becomes the default copilot for analog design or a sharp acquisition for an incumbent, it is asking a question the rest of the AI industry has mostly skipped: what happens when you point these tools at the work that was supposed to be too hard, too tacit, too human to automate. The answer, for analog at least, is being written now.

#analog#circuit-design#ai-agents#semiconductors#eda#yc-p26#chip-design#hardware