PRIVATE · MPC CUSTODY · Fireblocks

Full Stack Engineer, Blockchain

A London full-stack seat on the access path: the screens and services institutions use to reach a chain without holding the key.

You are deciding whether to take illiquid equity in the category leader of institutional wallet infrastructure, four years after its last disclosed valuation, in a London building seat rather than a research seat.

Blockchain Lab analysis, for a candidate deciding whether to apply. We are not the employer. Compensation on this posting: Not disclosed.

Listing age

5 days

Equity

Private. Illiquid.

Last priced round

$8 billion

Where

London

Status: Open on the employer board — checked 2026-10-06
Board updated: 2026-10-01 · 5 days before this check
Location: London
Remote eligibility: London
Employment: Not disclosed
Compensation: Not disclosed
Experience, as stored: Full-stack engineering. Compensation is not in the public feed.
Original post date: Not disclosed

Apply on the employer site The company Practice project

This seat

Blockchain Lab analysis

Routing, protection, and multi-chain transaction flow on the product Fireblocks already sells.

It does not own the MPC cryptography research, and it should not casually own policy exceptions. If your interview drifts into 'move fast and bypass quorum', leave.

Fireblocks won procurement because a policy engine can say no. Full-stack work on that path is a security job that happens to have a UI. A pixel that hides a chain, a gas asset, or a destination is an incident.

The company last priced itself at $8 billion in January 2022 and has not published a new mark. A 2026 model is far lower. Your equity is illiquid. The London seat will not change that. Price the cash.

Dynamic and Tres were acquired in late 2025 and early 2026. You may inherit another team's flows in the first half-year. Ask which codebase is the one you would open on day one.

Board updated 1 October 2026. Fresh. Location is London, not remote-worldwide.

The company you would actually join

Blockchain Lab analysis

Public reporting and the employer’s own releases. Not a relationship with Blockchain Lab. Not a credit opinion.

Founded: 2018, in Israel. Headquarters now New York.
Base: New York, with a London role on this desk. The product is global; the entity that employs you may not be.
Status: Private. No banking charter of the Anchorage type. Revenue is not disclosed.
People: PitchBook listed about 966 employees. Treat that as a database estimate, not a payroll file.

Fireblocks won the institutional wallet because it sold a control system, not a key. Policy, quorum, and a network of counterparties are the product a bank can show an examiner. The Series E in January 2022 priced that lead at $8 billion, on $550 million of new money, after a Series D six months earlier at $2 billion. The company has not published a new priced round since. PitchBook's undated-amount 2024 and 2026 entries say capital may have moved. They do not say the $8 billion mark was refreshed.

A September 2026 model on DefiLlama marked the company near $2.64 billion. Use it only as a warning that secondary opinion and the last round have diverged. Your option strike, if you receive one, will be set by the board, not by that model, and you may not be able to sell it. Ask what the last 409A or board mark was. They may not tell you. The silence is information.

The company has been buying. PitchBook records an acquisition of Dynamic in October 2025 and of Tres Finance in January 2026. Sacra describes a stablecoin payments network launched in September 2025. The surface area a London full-stack engineer inherits is wider than 'sign a transaction': routing, protection, issuance, and other teams' products that now have to feel like one console. Revenue remains unpublished. Headcount near a thousand, if the database is even roughly right, means this is a scale-up with process, not a twelve-person lab.

Founders

Michael Shaulov

Co-founder and CEO

Israeli founder. Previously founded Lacoon Mobile Security, later acquired by Check Point, and is widely described as a former member of Unit 8200. The company's culture is security-engineering first, exchange-product second.

Idan Ofrat

Co-founder and CTO

The technical co-founder behind the MPC and enclave design. A full-stack engineer on the blockchain access path is downstream of this architecture, not beside it.

Pavel Berengoltz

Co-founder

The third founder, associated with product and systems leadership. Three-founder Israeli security companies tend to keep a high bar on threat models and a low tolerance for demo-ware. Expect that.

What the company sells

MPC wallet platform

Key shares split across enclaves so no single machine holds a signing key. The policy engine sits in hardware isolation (SGX, Nitro) and decides what a transaction is allowed to be.

Network

A connectivity layer among institutions. Sacra describes on the order of 2,000 counterparties. That number is a profile's, not a figure we re-counted.

Tokens and payments

Issuance across many chains, and a stablecoin payments network Sacra dates to September 2025. The London full-stack seat is on the path users walk to reach those chains.

Capital

Last priced round

$8 billion

January 2022. Four and a half years old.

Capital raised

About $1.04 billion

Sacra and CB Insights agree on the total. Round-by-round sums above are the disclosed ones.

2026 model mark

About $2.64 billion

DefiLlama estimate as of 21 Sep 2026. A model, not a round. The gap to $8 billion is the point.

Revenue

Not disclosed

Private. CB Insights has hinted at historical revenue behind a paywall. We will not guess.

Jun 2019
Series A
$16 million
DefiLlama funding table, as of 5 Oct 2026.
Nov 2020
Series B
$30 million
Same table. Valuation not disclosed there.
Mar 2021
Series C
$133 million at about $850 million
The first clearly priced step into unicorn territory.
Jul 2021
Series D
$310 million at about $2 billion
Six months from C to D. The category was repriced in a single cycle.
Jan 2022
Series E
$550 million at $8 billion
Co-led by D1 Capital and Spark. Sequoia, Coatue, Ribbit, and Paradigm were among the names on the round. Earlier books include Index, General Atlantic, CapitalG, and BNY Mellon.
May 2024 and Jan 2026
Later-stage VC, amounts undisclosed
Not disclosed
PitchBook records completed later-stage deals on 19 May 2024 and 1 Jan 2026, with no public amount or valuation. Do not invent a new post-money from silence.

What should change your mind

Valuation gap. An $8 billion headline and a much lower third-party mark cannot both be your mental model.
No charter. Competitors with a trust or bank charter have a regulatory asset Fireblocks has not matched. That can matter the day a bank procurement team scores vendors.
Illiquid equity and undisclosed revenue. You cannot underwrite the grant.
Acquisition digestion. Two bought companies in five months changes the codebase you join.

Ask them

What is the current board valuation, and is there a tender?
Which product does this London seat ship in the next two quarters: network, policy, tokenization, or payments?
Who is the UK employing entity, and is sponsorship offered? The posting says London. It does not say visa.
How are Dynamic and Tres being folded into the console this role touches?

Sources

If a figure is not in those sources, it is not in this brief on purpose.

How the first months would actually go

Illustrative preparation

Not the employer’s onboarding plan.

Days 1–30: ship nothing user-facing that touches signing. Learn the policy language.
Days 31–60: one multi-chain fix with a test for the chain that behaves differently.
Days 61–90: a short note on a flow you would not simplify, and why.

A week you can rehearse

Click the path an operator uses to send. Count the approvals.
Name the chain-specific failure: a nonce, a fee asset, a reorg, a policy that matched the wrong destination.
Read the enclave boundary. Know what the browser is never allowed to decide.

What to take into the room

Illustrative preparation

Walk a transaction from click to signature to inclusion. Say where the policy sits.
How do you test a UI whose dangerous state is a wrong address that looks right?
What have you operated, not just rendered?

Proof you can build before you apply

The wallet-policy lab: an approval limit and a person who can stop a payment. Synthetic. The point is the stop, not the animation.

Open Policy-controlled wallet. A simulated wallet with an approval limit and a person who can stop a payment.

Walk away if

They describe the $8 billion round as the current value and will not discuss a later mark.
The seat is a rotation across three acquired products with no owner.
London means a contractor through an agency they disclose only at offer.

What the employer actually wrote

Employer stated. Fireblocks wants a London full-stack engineer on the access path institutions use to reach chains: routing, protection, and multi-chain transaction flow.

Design and build robust, scalable backend services supporting high-volume on-chain transaction flows across multiple blockchain networks — both EVM and non-EVM.
Own end-to-end development of backend components and APIs — from architecture decisions to production deployment.
Lead integrations with DeFi protocols, on-chain data sources, and blockchain nodes across a wide range of chains and ecosystems.
Research and evaluate emerging blockchain technologies, protocols, and standards to keep Fireblocks at the cutting edge.
Optimize existing production systems for performance, reliability, and security — reducing latency and increasing throughput.

Source: the employer’s public Greenhouse record, job 4695814006. Open the original. First seen by this desk 2026-10-06. Nothing above the fold is a substitute for that page.

A reading of the work

Blockchain Lab analysis. These lines are a reading of the advertisement. They are not extra hiring requirements.

Show who can sign, who can broadcast, and who can stop a payment.
Treat a bridge credit and a source debit as two facts until both are final.
Put policy limits in the transaction path, not in a wiki.

Still not disclosed

Compensation, unless a figure appears in the header. None of these eighteen postings stated one.
Closing date, and the day the role was first published. The board timestamp is an update.
Visa sponsorship, on-call, and the employing subsidiary.

Not a recommendation to apply. Not an employer assessment. Figures from public reporting move, and a database is not a filing. How this desk labels evidence. Report a listing.

Fireblocks · London · pay not disclosed

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