Zen Crypted Backend Developer

server.txt

Zen Crypted Backend Developer
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Statement of Work – Backend Developer (Elixir / Erlang / ASN.1)

*Project*: Development and enhancement of secure military-grade instant messaging server
*Position*: Senior/Middle Backend Developer (Elixir primary, Erlang/OTP understanding required)
*Project context*: The company is building a high-security chat platform for defense/government use cases.
 The backend is based on the open-source CHAT server, which implements a custom ASN.1/DER-encoded protocol
 over TCP/QUIC with full X.509 CMS envelope encryption, OCSP/LDAP validation, ephemeral messages,
 and standards compliance (RFC 5280, 5652, 8551, ДСТУ 4145, etc.).

Scope of Work (main deliverables):

* Deep code audit and refactoring of the existing Elixir/Erlang codebase:
* Review ASN.1 modules (priv/v2/CHAT-v2.asn1 + related PKIX/CMS modules)
* Optimize Mnesia usage for message delivery / persistence
* Harden crypto operations (crypto / public_key / ssl modules)

Implementation / enhancement of military-specific features:

* Integration of Ukrainian national crypto algorithms (ДСТУ 4145 / ДСТУ 4146 where applicable)
* Support for post-quantum key exchange primitives (if roadmap includes)
* Enhanced certificate enrollment flows (CMPv2 / EST / SCEP)
* Audit logging compliant with defense standards (tamper-evident, exportable)
* Granular access control and zero-trust message routing

Protocol evolution:

* Extend ASN.1 schema for new message types (e.g., file transfer with large attachments,
  voice/video signaling stubs, MLS-like group keying if required)
* Implement QUIC transport improvements (0-RTT, connection migration)
* Add optional federation support (via XMPP/OMEMO-like bridging or native)

Security hardening & compliance:

* Side-channel resistance improvements
* FIPS-like mode (or equivalent) for crypto primitives
* Preparation for external security audit / pentest
* OCSP stapling, CRL checking, DNSSEC integration

DevOps & release engineering:

* Improve mix release process, Docker / systemd packaging
* Monitoring / metrics (Prometheus / telemetry)
* CI/CD pipeline enhancements (tests coverage > 85%)

Required skills & experience (for job/CV screening):

* 4+ years commercial experience with Elixir (or strong Erlang/OTP transferable)
* Deep understanding of Erlang/OTP behaviors, supervision trees, gen_server / gen_statem
* Experience with cryptography in production (OpenSSL / Erlang :crypto, X.509, CMS/S-MIME, ECDSA / Ed25519 / X25519)
* Practical work with ASN.1 (encoding/decoding, custom compilers, BER/DER/PER)
* Familiarity with PKI infrastructure (CA, OCSP, LDAP, CMP/EST)
* Bonus: experience in defense/military/government projects, QUIC, post-quantum crypto, Mnesia / DETS
* Understanding of secure protocol design (avoiding common pitfalls like replay / downgrade attacks)
* English (Upper-Intermediate) + Ukrainian (advantage)

Nice to have:

* Experience with N2O.DEV, ERP.UNO open source stack
* Knowledge of MLS (Messaging Layer Security) RFC

Estimated engagement: Full-time / 6–12 months initial contract with extension option
Success criteria: Stable, auditable server passing internal crypto verification + security review;
new features merged into fork/main branch.