One of my side project:

image du logo de

It’s been a few months since one of my per­son­al projects get on­line. Name­ly, http­s://b­back­.me, a ser­vice to help you find your lost items with the help of peo­ple!

This ser­vice is based on the ob­ser­va­tion that most peo­ple are will­ing to re­turn a found ob­ject to its own­er, if on­ly they would be able to con­tact him. Thus, the num­ber of posts on so­cial net­works about peo­ple hav­ing found lost items and seek­ing for their own­er.

How it works logo

The main idea — which in it­self is not new — is to mark ob­jects with an iden­ti­fi­er that al­lows the per­son who finds the ob­ject to con­tact its own­er. The nov­el­ty is to mark ob­jects with a short in­ter­net ad­dress­es (URL), rec­og­niz­able as such.

The main char­ac­ter­is­tics are as fol­lows:

  • The ser­vice is free of charge and re­lies on us­er do­­na­­tions to bal­ance op­er­at­ing cost­s.

  • Each per­­son can choose the do­­main name that they think is most like­­ly to be rec­og­nized or un­der­s­tood by the per­­son who finds the ob­­jec­t.

    For ex­am­ple, in France, we may use or ren­ In An­glo-Sax­on coun­tries, bback­.org and bback­.me will be more suit­able. For the Dutch, kwi­ will be more ap­pro­pri­ate. More gen­er­al­ly, the do­mains and are al­so avail­able.

We do not sup­ply la­bels be­cause it is dif­fi­cult to pro­vide for­mats suit­able for dif­fer­ent us­es. You can use any means at your dis­pos­al to mark your ob­ject­s.

On a per­son­al lev­el, I fre­quent­ly use la­bels pro­duced with the help of a la­bel print­er (€20 on line), or tex­tile la­bels buyed on­line.

Feel free to con­sult the home­page and FAQ for more in­for­ma­tion,

Organization logo

I set up as an “au­to-en­trepreneur” in or­der to legal­ly host my per­son­al projects that could gen­er­ate costs and fi­nan­cial in­come. My “stage” name is An­tipo­dae. I will have oth­er projects to present to you in the com­ing month­s.

I had some con­cern about the cost of be­ing an “au­to-en­trepreneur”, es­pe­cial­ly the CFE (co­ti­sa­tion fon­cière des en­trepris­es), but it is pos­si­ble to avoid this tax if you don’t have any fi­nan­cial in­come.


On the tech­ni­cal side, the site is de­vel­oped in Python with the frame­work We­b2py. It is host­ed by Google App En­gine.

The we­b2py frame­work al­lows, tak­ing in­to ac­count the con­straints of the GAE NoSQL database, to de­vel­op an ap­pli­ca­tion that can be host­ed on GAE, but al­so be mi­grat­ed un­der a more tra­di­tion­al en­vi­ron­ment if nec­es­sary. This so­lu­tion was cho­sen so as not to be locked in the GAE ecosys­tem if it no longer met the need.

The tests are de­vel­oped with the help of Pytest and Splin­ter which in turn re­lies on Se­le­ni­um to per­form UI test­s. Con­tin­u­ous in­te­gra­tion is man­aged by an in­stance of Jenk­ins.

The pay­ment ser­vice is pro­vid­ed by Stripe. In­te­gra­tion tests use Vcr­py to re­play queries and an­swers from Stripe to save time and al­low for off­line tests re­play.

Send­ing mail is an im­por­tant com­po­nent of the ser­vice and is there­fore du­pli­cat­ed be­tween an in­ter­nal­ly man­aged Ex­im server, the Send­grid ser­vice and the mail send­ing ser­vice in­clud­ed with the GAE ser­vice as a last re­sort.


The ser­vice is com­posed of sev­er­al iden­ti­cal sites, with the same name (ren­, bback­.org, kwi­,…). All im­ages of the site are gen­er­at­ed from a source im­age in SVG for­mat, then trans­lat­ed ac­cord­ing to the lan­guage and site of des­ti­na­tion, with the help of the trans­la­tion tools pro­vid­ed by the we­b2py frame­work. For ex­am­ple for the home page strip:

French image for the site

Im­age in eng­lish for the site ren­

image in English for the site

Im­age in Eng­lish for the site bback­.me

In the fol­low­ing ex­am­ple, note that the name of the ob­ject en­tered by the us­er on his screen is trans­lat­ed.

image in French

French im­age for ob­ject reg­is­tra­tion

image in English

Im­age in Eng­lish for ob­ject reg­is­tra­tion

The frame of the site is built on a home made tem­plate boost­strap.


I hope this site will be of some help. Feel free to use it and to give feed­back.