Matt Bid­dulph is the Lead Devel­oper on social net­work for trav­ellers, Dopplr. I inter­viewed him recently for my Dopplr review on Web Worker Daily. I’m post­ing the full inter­view here so that you can read all the really inter­est­ing things Matt had to say. Once more into the breach!

I’m speak­ing with Matt Bid­dulph, lead devel­oper at social com­put­ing and travel startup Dopplr. Matt, hi. Wel­come to acidlabs!

Thanks Steve. Nice to be here.

So, let’s get started. Tell me a lit­tle about your­self and the other peo­ple behind Dopplr.

The Dopplr team is made up of five peo­ple: Matt Jones, Marko Ahti­saari, Dan Gill­mor, Lisa Sounio and myself. We’re all fre­quent trav­ellers based in Lon­don, Helsinki and Cal­i­for­nia. I’m the lead devel­oper and I’m par­tic­u­larly nomadic; in the last 18 months I’ve lived in the French alps, Ams­ter­dam and San Fran­cisco, and I’m cur­rently spend­ing a month in Mon­treal. Code for Dopplr has been writ­ten in the Vir­gin First Class lounge at SFO, in Econ­omy seats on Air India, and in cafes in Paris.

Describe your archi­tec­ture — hard­ware and soft­ware. As you grow and the site takes off (par­don the pun), this will obvi­ously be a con­cern. Where are your contingencies?

We run with Ruby on Rails, my favourite web frame­work, on top of the usual Open Source stack: Linux, MySQL, mem­cached and so forth. I’m a huge fan of Rails and I’ve been using it since late Sum­mer 2005 when I started work on the BBC Pro­gramme Cat­a­logue project — http://​open​.bbc​.co​.uk/​c​a​t​a​l​o​g​u​e​/​i​n​fax. As we see from the suc­cess of pop­u­lar Rails apps like Twit­ter, the Rails com­mu­nity is quickly matur­ing and grow­ing, and learn­ing how to scale. I’m con­fi­dent that we’ll be able to use com­mod­ity ser­vices like those pro­vided by Joyent and Ama­zon EC2 to scale our sys­tem when the time comes.

Dopplr’s an inter­est­ing con­cept — social com­put­ing and travel hasn’t been done in this way before. What was your moti­va­tion behind Dopplr?

All of us at Dopplr spend way too much time in air­ports and hotels, and we all appre­ci­ate the serendip­ity that travel can bring. Our social net­work is very impor­tant to us, and this is what brought us together to make Dopplr. It all started when Marko noticed he was spend­ing sig­nif­i­cant time every week writ­ing emails to peo­ple telling them where he was going to be, to see if there was a chance to meet up. He realised that social soft­ware could help here. If he recorded his trav­els in one place and all his friends did too, he would save time, and dis­cover the missed coin­ci­dences and serendip­ity that hap­pen con­stantly in a net­work of inter­na­tional friends. There are many ser­vices that focus on what you’re doing right now or what you have been doing — we focus on the future.

Your loca­tion and travel plans are a very per­sonal thing, and so we knew that pri­vacy was an impor­tant issue. We think of Dopplr as as ‘inti­mate’ social net­work, where trust is impor­tant. This is why we made it invite-​​only; every­one who joins Dopplr is tak­ing their place in an exist­ing net­work. We are very care­ful to only reveal infor­ma­tion to peo­ple you have explic­itly told us to.

Unlike other travel focussed Web 2.0 sites, Dopplr is about con­nect­ing the peo­ple involved. How do you plan to build out the func­tion­al­ity so that users can get more value from Dopplr?

The thing we value the most is what we call the Dopplr Moment — when you dis­cover a coin­ci­dence with a friend in a far-​​flung town and have an unex­pected beer, meet­ing or meal.

In our first three months, we’ve only just scratched the sur­face of what’s pos­si­ble there. For exam­ple, imag­ine you are going to a Paris for the first time. It may be that, unknown to you, a friend-​​of-​​a-​​friend lives there and could show you around town. Dopplr could prompt your friend to make that introduction.

We also realise that Dopplr is only as use­ful as the data peo­ple put into it, so we’ll be con­cen­trat­ing on adding ways to auto­mat­i­cally get your data in. We could be tak­ing a feed from your travel agents, screen-​​scraping from your air­line con­fir­ma­tion emails, or sub­scrib­ing to your pub­lic Google calendar.

Tell us about some of the unique fea­tures of Dopplr and how they work.

One fea­ture we’re very excited about and intend to build on in the future is text-​​messaging. Right now, you can reg­is­ter your mobile num­ber with Dopplr and use SMS to record your trips, add notes or invite new peo­ple to join. We think you should be able to access Dopplr any way you want when you’re on the road, so we’ll be extend­ing this to IM and email (par­tic­u­larly good for Black­berry users) before long. Of course, we already have iCal and Atom feeds as part of the product.

Also on the theme of access to infor­ma­tion any way you want it is the API that’s cur­rently in devel­op­ment. We’ve given pre­view access to some of our friends and they’ve already built inter­est­ing mashups like this Google Earth visu­al­i­sa­tion.

You’ve got a pretty well-​​defined tar­get audi­ence. How do you plan to lever­age those peo­ple into a money-​​making model for Dopplr? Or are you plan­ning a dif­fer­ent approach to Dopplr? It obvi­ously lends itself nicely to tar­geted adver­tis­ing, for example.

We’re explor­ing the pos­si­bil­i­ties about mak­ing Dopplr into a money-​​making ven­ture, but we’re focus­ing much more right now on mak­ing it a fun and vibrant com­mu­nity that will grow. We know we’ve got a great idea and we’re con­cen­trat­ing on prov­ing that value.

Cli­mate change caused by travel has been in the news recently. Where does Dopplr stand on the issue of global warm­ing with such a jet­set­ting community?

It was very impor­tant to us right from the begin­ning that Dopplr shouldn’t be a place to show off how much travel you do. Instead, it should be a way to opti­mize your travel by dis­cov­er­ing serendip­ity, and hope­fully sav­ing a trip from time to time. Smart travel, or per­haps even Travel 2.0.

We intend to add tools to mea­sure the car­bon impact of your trav­els and help you in off­set­ting them. For exam­ple, last year I trav­elled more than 40,000 miles by air. At the end of the year I added up all my plane tick­ets in order to off­set it at ter​ra​pass​.com. This took me an hour’s work, and is some­thing that could be cal­cu­lated in an instant using the data on Dopplr.

Matt, thanks for your time. Good luck to you and the Dopplr Team!

Thanks again, Steve. Don’t for­get to tell your read­ers that they can fol­low our progress on the Dopplr blog. We’re also tak­ing signups for the beta pro­gram.

I’ve been a mem­ber of Dopplr for a few months now, and I’m really enjoy­ing watch­ing the fea­ture set grow almost weekly. Also, as an early adopter, I have invi­ta­tions to give away. If you’re some­one who knows me and wants an invi­ta­tion, drop me an email. If you don’t know me, tell me a story that con­vinces me I should invite you. Leave your sorry enter­tain­ing tale in the com­ments and I just might shoot you an invitation!