Software producer and publisher · Warsaw, Poland

Software builtside by side.

Side by Side produces and publishes its own SaaS platforms. We take processes that normally run on spreadsheets, e-mail and paper, and turn them into software that has to hold up legally as well as technically.

See the products Talk to us

platforms we produce and publish: 2; platforms we produce and publish
markets we ship into: PL / ES; markets we ship into
design, build, release and run: End to end; design, build, release and run

Products

What we make.

We build software for the parts of a business that carry legal and financial weight: agreements, identity, settlements and invoicing. Work that normally means paperwork, spreadsheets and chasing people by e-mail becomes one flow that runs itself and leaves a record behind.

Live on web, iOS and Android

trustay®

Rent out with peace of mind.

Rental agreements, electronic signature, handover protocols and settlements. Landlord and tenant in one place.

trustay® is a platform for renting out flats safely. The idea underneath it is that trust works both ways: both sides verify their identity, and both sides are rated, so a landlord knows who they are renting to and a tenant knows who they are renting from, before anything is signed.

How a tenancy runs

Verify identity
Add the property
Share the agreement
Sign electronically
Hand over with a protocol
Settle the rent

Mutual identity verification

Remote selfie and ID document checks on both sides of the deal, completed in moments. Provided by Veriff.

trustayScore™

Two-sided scoring and rating history between landlord and tenant, so both reputations are visible before signing.

Agreements drafted by law firms

Standard, occasional and institutional tenancy, rooms and parking spaces, prepared by leading law firms.

Electronic signature

eIDAS signing in a few minutes, with a qualified signature where the law requires one and the statutory protections that come with it.

Handover protocols

The condition of the flat photographed at handover and at return, with faults reported in the app and kept in one history.

Settlements and invoicing

Rent, fees, utilities and deposits, annexes and terminations, with invoices sent to KSeF.

Markets: Poland (PLN) and Spain (EUR)
Platforms: Web app, native iOS and Android
Built for: Private landlords, companies and professional landlords
Pricing: One-off fee per agreement, no subscription. Free for tenants.

trustay.pl trustay.es

Proptech
Rental agreements
eIDAS signature
Identity verification
KSeF
iOS and Android

B2B web platform

Nodus Blue

The settlement system for TV channel distribution.

Operators, contracts, subscriber reports, settlements, invoicing and accounting joined into one automated flow.

Nodus Blue replaces spreadsheets and manual invoicing with a single panel that works out what each operator owes, issues the invoice and sends it in the operator's own language, under Polish regulations. It is built for broadcasters and distributors settling with dozens of cable and IPTV operators, in several currencies, on royalty or flat-fee terms. Nodus is Latin for knot: the knot that ties a whole distribution business together.

The month, end to end

Operators
Subscriber reports
Settlement
Invoice and KSeF
Accounting office

From report to invoice, with no clicks

An operator files a report in their portal, by e-mail or over IMAP. The system approves it, calculates what is owed, issues the invoice and sends it out, either on a set day each month or the moment the report lands.

Contracts and operators

Royalty and flat-fee contracts, channels, projects, rates and contacts, with counterparty checks against the VAT white list and VIES in one click.

Subscriber reporting

Operators report subscriber numbers per channel through their own panel, with corrections, estimates, completeness checks and average household figures.

Compliance built in

KSeF, the VAT white list, VIES, NIP, PESEL and IBAN validation, AML monitoring for sanctions and PEP signals, and eIDAS documentary evidence, all as standard.

Sales, costs and collections

PDF and KSeF e-invoices, recurring and corrective invoices, multi-currency with exchange rates, cost invoices imported from KSeF and e-mail, payment files ready for the bank, and automated payment reminders.

Month end in one click

Revenue and costs by group and project, bank transactions matched to invoices, and every invoice packed into an archive and sent to the accounting office in the language you choose.

Built for: Broadcasters and distributors of TV channels
Counterparties: Dozens of cable and IPTV operators on royalty or flat-fee terms
Languages: PL, EN and RO, each operator written to in their own language
Access: Passwordless login, roles, permissions and a full activity log

Multi-tenant
Multi-currency
KSeF
AML monitoring
eIDAS
Automated invoicing

Approach

We publish software we have to live with.

Both products are ours. That changes how they get built: nobody hands the repository over and walks away from the consequences.

Regulated by design

KSeF, eIDAS, the VAT white list, VIES, AML screening and identity checks are part of the product, not a compliance project bolted on afterwards.

We run what we publish

Real contracts, real payments and real money move through our platforms every month. Bugs are our support tickets, so quality is not an abstraction.

Built to be operated

Multi-tenant, multi-currency, multi-language, with roles, permissions and a full audit log, so a small team can run a large book of business.

Capabilities

What we are good at.

The engineering behind trustay® and Nodus Blue, and the work we take on with partners who need the same things built.

Regulated workflows

Document and money flows that have to satisfy a regulator as well as a user. Shipped in production, not in a proposal.

eIDAS electronic signature
KSeF e-invoicing
AML screening and KYC

Billing and settlements

Rates, royalties, recurring invoicing, corrections and reconciliation, in several currencies at once.

Royalty and flat-fee models
Multi-currency with rates
Bank matching and payment files

Multi-tenant SaaS

Platforms where many companies, roles and permissions live on one system without leaking into each other.

Tenant isolation
Roles and permissions
Full activity log

Web and native mobile

One product language across a web app and native iOS and Android, in every market language we ship.

Design systems
Native iOS and Android
PL, EN, RO and ES

Integrations

The public registers, mailboxes, banks and partner APIs a business actually depends on, wired in and kept working.

Public registers and e-invoicing
IMAP and document intake
Banking formats

Run and operate

Infrastructure, releases, monitoring and support after launch, because publishing software is where the work starts.

Infrastructure as code
Monitoring and alerting
Long-term support

Stack

Tools we reach for first.

Deliberately conventional choices. The product should be the interesting part of the system, not the framework underneath it.

Front end

TypeScript
React
Next.js
Tailwind CSS

Back end

Node.js
PostgreSQL
Prisma
REST and tRPC

Platform

Vercel
AWS
Docker
GitHub Actions

Quality

Playwright
Vitest
Sentry
Code review

Contact

Talk to us.

Whether you want to use one of our platforms, publish something together, or have us build the regulated part of your product, send a few lines. You will get a real reply, usually within two business days.

Side by Side Sp. z o.o.

Pl. Bankowy 2

00-095 Warszawa

Poland