Open-source stack for remote SaaS startups

TL;DR

Who this list is for (and who it isn't)

You're a founder or technical co-founder running a remote-first SaaS startup. Pre-seed or seed. Three to ten people, mostly engineers and one or two on the commercial side. Your SaaS bill crept from $200 a month at founding to $600 a month around month nine. The renewals are stacking on top of each other. Runway is the only number you check more than once a day.

This is a migration list, not a build-from-scratch list. Every app below has been in production for years at companies bigger than yours. The point is not to convince you that open source is morally superior. The point is that six well-chosen apps, hosted by someone else, can cut a meaningful slice of recurring spend without forcing you to hire a sysadmin.

This list is not for you if any of the following describes your team:

• Two of your five people genuinely enjoy ops work. Self-hosting on a $24 production-class VPS with Coolify is a real path; you'll save another margin on top.

• You're a single-founder bootstrapper running mostly on free tiers. Your SaaS bill isn't big enough yet — come back at five seats.

• You have a hard regulatory requirement for an attested vendor. Buyers will ask you for documents DANIAN doesn't currently issue. A compliance-certified provider is the right fit today.

• You're deeply dependent on a specific GitHub Marketplace Action your CI/CD pipeline cannot replicate. The migration friction on that one is honest and named below.

If none of those, read on.

The cost frame, in numbers

Before the apps, the math. At five paid seats in mid-2026, the proprietary stack a remote SaaS startup typically runs looks roughly like this, using each vendor's published list pricing for the tier that actually works in production:

• Slack Pro at five seats: about $43.75/month on monthly billing, $36.25 on annual. Slack Pro is $7.25/user/month annual or $8.75 monthly.

• GitHub Team at five users: $20/month at $4/user/month. Startups that need SSO, SCIM or compliance features move to Enterprise Cloud at $21/user — $105/month at five seats. Add CI overage and the bill grows.

• Zapier Professional at 750 tasks: $29.99/month. Most growing startups hit the task cap and move to Team at $103.50/month for 2,000 tasks.

• Mixpanel Growth: free up to one million events, then $0.28 per thousand. A startup tracking three million events monthly pays around $560.

• 1Password Business at five seats: $39.95/month. 1Password Business is $7.99/user/month billed annually.

• Google Workspace Business Standard at five seats: $70/month. Workspace Business Standard runs $14/user/month.

Lower bound, all entry tiers, five seats: about $203 per month.

Realistic mid-range with one or two tools at the next tier and modest event volume: $400–$500 per month.

Upper bound with Enterprise GitHub, Zapier Team, Mixpanel Growth at three million events and Workspace at ten seats: $800+ per month.

The managed open-source equivalent on DANIAN is six apps at €9 each. €54/month, flat, with hardware, security updates, daily off-site backups, monitoring and 24/7 chat included. At roughly $1.08/€, that's about $58. Against the $400 mid-range that's a 7× reduction. Against the $800 upper bound it's nearly 14×.

The reduction is genuine. It's also not the whole story. Migration time costs money. Some workflows don't translate. The rest of this post names both sides.

How the six fit together

The stack is not random. The six apps cover the six surfaces a remote-first SaaS startup actually touches every day: where you communicate, where you write code, where you wire things together, where you measure what's working, where you keep secrets, and where you collaborate on documents.

The chat tier (Mattermost) is where the team lives. n8n watches for events across the stack — a new GitLab merge request, a Matomo conversion goal triggered, a Vaultwarden vault access — and posts them to the relevant Mattermost channel. GitLab's webhooks fire on every push, build and deployment. n8n decides which of them warrant the team's attention. Matomo feeds business-side dashboards that show conversion movement to non-technical co-founders without needing them to write SQL.

A team running this stack ends up with one place each thing lives, instead of seven SaaS dashboards that each cost twenty dollars a seat. The integration layer is n8n — the same n8n that replaces Zapier. The automation work pays double duty.

For startups that are mostly engineers, the natural pairing is GitLab + Mattermost + n8n on day one. Vaultwarden joins a week later once the team's password hygiene is bought-in. Matomo and OnlyOffice Docs usually arrive last, because product analytics and document collaboration are slower-burning needs that compound over months.

Region choice matters more than it looks. A São Paulo-based founding team running Mattermost shouldn't host it in Frankfurt — latency taxes every message. DANIAN's catalog runs across 21 datacenter regions on six continents. You pick the region per app, not per account.

How to start — phase the migration, don't switch everything in one weekend

Six apps in one weekend is the wrong play. The right phasing for most teams looks like this:

Week one — pick one app.

Week two — add a quiet one. 

Weeks three and four — the heavier ones. 

Month two — OnlyOffice Docs. 

If a migration stalls, stop. You don't need to ship all six. A four-app stack that works is better than a six-app stack nobody trusts.

Evaluate after fourteen days of real use, not after the first install. The first three days of any migration feel worse than the SaaS you left. The second week is when the actual fit becomes visible.

FAQ

What's the total cost of running this stack at ten people versus the SaaS equivalent?

At ten paid seats, the proprietary stack typically runs $500–$1,200/month depending on tiers, plus Mixpanel scaling and Zapier overages. The managed open-source equivalent on DANIAN runs €54/month flat for the base six apps. Expect €63–€81/month once GitLab is sized for a ten-developer CI workload. The gap widens as the team grows.

How much can a 5-person startup save annually by switching from SaaS to this open-source stack?

A five-person startup on mid-tier SaaS plans typically pays $400–$500/month on these six lines, which is $4,800–$6,000/year. The same six apps managed on DANIAN cost €54/month, roughly $700/year. Annual savings: $4,100–$5,300. At the upper SaaS bound of $800/month, savings reach $8,500+ per year.

Can my team actually migrate all six apps in one go?

No. Pick one app per week or per fortnight. Most teams hit four of the six in a quarter, leave OnlyOffice for the second quarter, and genuinely decide whether the sixth app is needed. A four-app open-source core paired with two SaaS lines that fit your workflow is a perfectly reasonable end state.

How long does the full six-app migration actually take in practice?

Calendar time: six to ten weeks for the full stack. Engineering time: roughly three to four engineer-weeks total, spread out. Mattermost takes a weekend to two weeks. Matomo and Vaultwarden are half-day setups each. GitLab needs one engineer-week. n8n needs a steady week. OnlyOffice is the longest tail because of document migration.

What if we rely on a specific GitHub Action that doesn't exist in GitLab CI?

Honest answer: keep that one workflow on GitHub, or rewrite the Action's logic as a few lines of GitLab CI YAML. Many GitHub Actions are thin wrappers around shell commands; rewriting in GitLab CI is usually quicker than expected. If the Action is a vendor's proprietary deploy tool, ask the vendor for a GitLab equivalent — most major vendors publish both.

Does Matomo offer the same analytical depth as Mixpanel for product analytics?

For 80% of what most SaaS startups actually do — goals, funnels, segmentation, conversion tracking, real-time dashboards — Matomo matches Mixpanel closely. For deep behavioural cohort analysis with ten-step retention math, Mixpanel's purpose-built UI is still ahead. Most pre-seed and seed startups don't run that depth of analysis; the gap matters past 50,000 monthly active users.

Will OnlyOffice open my existing Google Docs without breaking the formatting?

Mostly yes. OnlyOffice has the strongest Microsoft Office format fidelity in the open-source category, and Google Docs exported to .docx renders cleanly in OnlyOffice. Expect minor visual drift on documents with heavy custom styles, embedded charts, or unusual fonts. For most business documents — proposals, contracts, internal memos — the round-trip is clean.

Is Vaultwarden as secure as 1Password?

The core security model is identical to Bitwarden's because Vaultwarden implements the Bitwarden API; the same end-to-end encryption applies. The difference is operational maturity: 1Password runs a dedicated security team and a published bug bounty program. Vaultwarden's security depends on the operator (in this case, DANIAN) keeping the server patched, isolated and backed up — which is what €9/month covers.

Can we import historical Slack messages into Mattermost?

Yes. Mattermost ships an official Slack importer that handles channels, threads, direct messages, file uploads and user metadata from Slack's ZIP export. The import is automated for free Slack workspaces and Pro/Business plans. Plan for one to two days of preparation and one engineer-half-day to run the import for a small workspace.

Are these apps multi-tenant on shared infrastructure, or fully isolated?

Each app runs in its own hardened container with dedicated resource allocations, isolated networking and per-app backups. The underlying infrastructure is multi-tenant — that's what makes €9 per app possible. The boundary between containers is real, audited, and operationally identical to what we'd run if each app had its own VM.

Do these open-source apps support SSO and SAML for team logins?

Most do. Mattermost, GitLab, Matomo and OnlyOffice Docs support SAML and OIDC SSO on their open-source editions. n8n's SAML SSO sits behind its enterprise tier; for self-hosted use, OIDC integration is typically configured at the reverse proxy. Vaultwarden supports SSO via the SSO bridge that ships with Bitwarden Enterprise patterns.

How are daily backups handled and where are they stored?

Every app on DANIAN gets a daily off-site backup, included in the €9/month. Backups are encrypted and stored in object storage separate from the production infrastructure, in the region you pick. Restore is performed by support on request and tested as part of routine operations. The backup window is daily; finer cadences are available on the upgraded tiers.

Does n8n handle the same workflow volume as Zapier at scale?

Yes, and usually better. A single n8n instance on €9 of resources comfortably handles tens of thousands of workflow executions per day. Zapier's Team plan caps at 2,000 tasks per month at $103.50; n8n has no equivalent cap. The constraints are CPU and memory, not task quota — and DANIAN scales those at +€9 per vCPU when you need more.

Why GitLab Community Edition instead of one of GitLab's paid tiers?

GitLab CE includes source-code management, issues, merge requests, CI/CD pipelines, container registry, wiki and 80% of what most teams use Premium for. Premium ($29/user/month) adds advanced approvals, multiple reviewers and priority support. The top paid tier adds security scanning and compliance features. For a five-to-ten-person SaaS startup, CE is genuinely sufficient.

What happens if DANIAN goes down or we want to leave?

The underlying apps are open source. Daily off-site backups are part of the €9. You can export your data and stand up the apps elsewhere — on a VPS, a home server, another managed provider — at any time. There is a published “how to leave” guide. The OSS apps are yours; we just operate them.

Is n8n's Sustainable Use License a problem for using it internally at a SaaS startup?

No. The Sustainable Use License permits free use, modification and distribution for internal business purposes. It restricts only one thing: offering n8n itself as a hosted service to third parties (essentially preventing competing managed n8n products). A SaaS startup using n8n to run its own internal workflows sits well inside the licence's allowed uses.

Do these apps have mobile apps that work as well as the SaaS originals?

Mattermost, Bitwarden (used with Vaultwarden) and OnlyOffice Docs all ship polished iOS and Android apps that match the SaaS user experience closely. GitLab has a competent mobile experience via its responsive web app rather than a dedicated native app. n8n is an admin tool and doesn't need a mobile app. Matomo offers a mobile app for dashboard viewing.

Should we wait until after our Series A funding to migrate?

Almost certainly the opposite. Pre-funding, every dollar saved extends runway proportionally; the same €4,000/year saved is meaningful at pre-seed and trivial post-Series A. Post-funding, the team is bigger, integrations are deeper, and migration time is more expensive. The window where the math is best is pre-seed to early seed — before the SaaS stack is fully entrenched.

Can we run a hybrid stack — some of these apps with you, some elsewhere?

Yes, and most teams end up here. The six apps don't have to come from one provider. Some run Mattermost and GitLab on DANIAN and keep n8n on a separate self-hosted server. Some run Vaultwarden on DANIAN and keep Mixpanel on the SaaS for analytics depth. Mix freely.

At what team size does this open-source stack stop being cheaper than the SaaS equivalent?

It doesn't, mathematically. The DANIAN stack is flat at €9 per app; the SaaS stack scales per seat. At 25 people the SaaS bill is roughly $2,000–$3,500/month; the managed open-source equivalent is still €54–€100/month including resource upgrades. What changes at larger scale is the relative weight of migration time versus monthly savings — at 50+ people the migration is harder, but the math gap is also larger.

What about SSL certificates and custom domains — do we configure those ourselves?

Mostly no. DANIAN provisions SSL automatically through Let's Encrypt on every app instance and renews certificates without intervention. Custom domains are configured by the customer via DNS, with support performing the DANIAN-side wiring on chat request. Most teams complete custom-domain setup in under thirty minutes including DNS propagation.

Conclusion — what to do this week

Three concrete steps for a founder reading this on a Sunday evening with a runway spreadsheet open.

Audit your current SaaS spend, line by line. Pull the actual numbers from the invoices, not the rounded estimates. Most founders are off by 20–40% on what they think they're paying. The audit alone usually produces a “we can cut this” or two unrelated to any migration.

Pick the one app where the SaaS pain is sharpest. For most pre-seed SaaS teams that's Zapier — the task cap is the most aggravating per-dollar limit in the SaaS landscape. Or Mixpanel — event-based billing punishes growth. Run a 7-day free trial on the open-source equivalent. Don't commit to a six-app migration on a Sunday; commit to one app and see how it fits.

See the catalog for the full list of 150+ apps. See pricing for the per-app €9 floor and resource-scaling rules. Either way, test the fit on one app before you spend a euro.

The stack on this list isn't a religion. It's a budget arithmetic exercise dressed up as a tooling decision. The math is on the open-source side at this team size, and the migration is a defined piece of work, not an open-ended project. Either it pays back in four weeks or it doesn't. You'll know which by week two.