Specialty Software Engineer 3

Motion Recruitment; Concord (CA); Hybrid; USD 140,000 - 190,000; Full time

Job summary

Motion Recruitment is seeking a Specialty Software Engineer for a long-term contract in Concord, CA (Hybrid). The role focuses on building a blockchain-based system using Go, Cosmos SDK, and CometBFT, with emphasis on privacy-preserving primitives and scalable distributed architecture.

You will work on custom protocol development, cryptographic implementations, and data integrity across on-chain and off-chain components in a FinTech-centric environment.

Qualifications

• 4+ years in Specialty Software Engineering.
• 3+ years backend or systems programming in Go.
• 6+ months experience with elliptic curve cryptography (ECC).
• 1+ year experience with BFT, P2P, and state replication.

Responsibilities

• Consult on moderately complex initiatives and contribute to planning.
• Review challenges requiring in-depth evaluation of factors.
• Resolve issues and consult with others to meet deliverables.
• Collaborate with client personnel in Specialty Software Engineering.
• Architect and build a blockchain app using Go, Cosmos SDK, and CometBFT.
• Implement privacy-preserving primitives and optimize cryptographic ops.
• Engineer ABCI++ extensions for an on-chain MPC mixing network.
• Design KVStore state machine for homomorphic balances.
• Optimize crypto operations for low latency in distributed env.
• Build secure off-chain query layers and view-key auditing.

Skills

Go (Golang)

Distributed systems

ECC crypto

BFT consensus

P2P networking

Job description

Outstanding long-term contract opportunity! A well-known Financial Services Company is looking for a Specialty Software Engineer in Concord, CA (Hybrid).

Work with the brightest minds at one of the largest financial institutions in the world. This is a long-term contract opportunity that includes a competitive benefit package! Our client has been around for over 150 years and is continuously innovating in today's digital age.

Contract Duration: 12 Months

Required Skills & Experience

• 4+ years of Specialty Software Engineering experience, or equivalent demonstrated through one or a combination of the following: work or consulting experience, training, military experience, education.
• 3+ years of experience in backend or systems programming, with expert-level proficiency in Go (Golang)
• 6+ months of experience with Elliptic Curve Cryptography (ECC)
• 1+ year of experience with BFT consensus algorithms, P2P networking, and state replication; reliable, distributed systems experience

Desired Skills & Experience

• Blockchain Core: Deep experience with Cosmos SDK and CometBFT. Comfort building custom modules and modifying consensus logic, not just deploying smart contracts
• Pedersen Commitments (Homomorphic encryption properties)
• Zero-Knowledge Proofs (specifically Bulletproofs or Sigma protocols)
• Math-to-Code: Demonstrated ability to read academic whitepapers/preprints and translate mathematical specifications into functioning code
• Experience with MPC (Multi-Party Computation) or Verifiable Secret Sharing (VSS) schemes
• Familiarity with the Ristretto255 curve or libraries like gnark-crypto
• Background in FinTech, payment systems, or high-frequency trading platforms
• Understanding of the Account Model vs. UTXO Model trade-offs in privacy-preserving ledgers

What You Will Be Doing

• Consult on or participate in moderately complex initiatives and deliverables within Specialty Software Engineering and contribute to large-scale planning related to Specialty Software Engineering deliverables.
• Review and analyze moderately complex Specialty Software Engineering challenges that require an in-depth evaluation of variable factors.
• Contribute to the resolution of moderately complex issues and consult with others to meet Specialty Software Engineering deliverables while leveraging solid understanding of the function, policies, procedures, and compliance requirements.
• Collaborate with client personnel in Specialty Software Engineering.
• Core Protocol Development: Architect and build a custom blockchain application using Go, Cosmos SDK, and CometBFT (Tendermint)
• Cryptographic Implementation: Implement and optimize privacy-preserving primitives, specifically Pedersen Commitments and Bulletproofs (Range Proofs), ensuring no trusted setup is required
• Consensus Customization: Engineer custom ABCI++ extensions (specifically PrepareProposal and Vote Extensions) to implement an on-chain Multi-Party Computation (MPC) mixing network
• State Machine Design: Design a custom KVStore state machine that manages homomorphic encrypted balances (Elliptic Curve points) instead of plaintext integers
• Performance Engineering: Optimize cryptographic operations (scalar multiplication, point addition) for low latency and high throughput in a distributed environment
• Auditing Infrastructure: Build secure off-chain query layers and "view key" mechanisms that allow for granular, permissioned regulatory auditing